diff --git a/core/src/main/java/org/teavm/ast/CastExpr.java b/core/src/main/java/org/teavm/ast/CastExpr.java
index 8a52bc0ce..b20ad0d08 100644
--- a/core/src/main/java/org/teavm/ast/CastExpr.java
+++ b/core/src/main/java/org/teavm/ast/CastExpr.java
@@ -21,6 +21,7 @@ import org.teavm.model.ValueType;
 public class CastExpr extends Expr {
     private Expr value;
     private ValueType target;
+    private boolean weak;
 
     public Expr getValue() {
         return value;
@@ -38,6 +39,14 @@ public class CastExpr extends Expr {
         this.target = target;
     }
 
+    public boolean isWeak() {
+        return weak;
+    }
+
+    public void setWeak(boolean weak) {
+        this.weak = weak;
+    }
+
     @Override
     public void acceptVisitor(ExprVisitor visitor) {
         visitor.visit(this);
@@ -48,6 +57,7 @@ public class CastExpr extends Expr {
         CastExpr copy = new CastExpr();
         copy.value = value.clone(cache);
         copy.target = target;
+        copy.weak = weak;
         return copy;
     }
 }
diff --git a/core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java b/core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java
index be885aec4..da209c4b2 100644
--- a/core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java
+++ b/core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java
@@ -214,6 +214,7 @@ class StatementGenerator implements InstructionVisitor {
         expr.setVariableIndex(insn.getReceiver().getIndex());
         expr.setValue(Expr.var(insn.getValue().getIndex()));
         expr.setTarget(insn.getTargetType());
+        expr.setWeak(insn.isWeak());
         assign(expr, insn.getReceiver());
     }
 
diff --git a/core/src/main/java/org/teavm/backend/c/generate/CodeGenerationVisitor.java b/core/src/main/java/org/teavm/backend/c/generate/CodeGenerationVisitor.java
index d8d34e7e8..b53728ba9 100644
--- a/core/src/main/java/org/teavm/backend/c/generate/CodeGenerationVisitor.java
+++ b/core/src/main/java/org/teavm/backend/c/generate/CodeGenerationVisitor.java
@@ -1056,6 +1056,11 @@ public class CodeGenerationVisitor implements ExprVisitor, StatementVisitor {
 
     @Override
     public void visit(CastExpr expr) {
+        if (expr.isWeak()) {
+            expr.getValue().acceptVisitor(this);
+            return;
+        }
+
         if (expr.getTarget() instanceof ValueType.Object) {
             String className = ((ValueType.Object) expr.getTarget()).getClassName();
             if (!context.getCharacteristics().isManaged(className)) {
diff --git a/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java b/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java
index 2862f3ddf..feeee4ddf 100644
--- a/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java
+++ b/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java
@@ -878,7 +878,7 @@ public class StatementRenderer implements ExprVisitor, StatementVisitor {
 
     @Override
     public void visit(CastExpr expr) {
-        if (context.isStrict()) {
+        if (context.isStrict() && !expr.isWeak()) {
             if (expr.getLocation() != null) {
                 pushLocation(expr.getLocation());
             }
diff --git a/core/src/main/java/org/teavm/backend/wasm/gc/PreciseTypeInference.java b/core/src/main/java/org/teavm/backend/wasm/gc/PreciseTypeInference.java
index bc1f64780..2474e38da 100644
--- a/core/src/main/java/org/teavm/backend/wasm/gc/PreciseTypeInference.java
+++ b/core/src/main/java/org/teavm/backend/wasm/gc/PreciseTypeInference.java
@@ -20,19 +20,15 @@ import org.teavm.model.MethodReference;
 import org.teavm.model.Program;
 import org.teavm.model.ValueType;
 import org.teavm.model.analysis.BaseTypeInference;
-import org.teavm.model.instructions.InvocationType;
 
 public class PreciseTypeInference extends BaseTypeInference<PreciseValueType> {
     public static final PreciseValueType OBJECT_TYPE = new PreciseValueType(ValueType.object("java.lang.Object"),
             false);
     private ClassHierarchy hierarchy;
-    private WasmGCMethodReturnTypes returnTypes;
 
-    public PreciseTypeInference(Program program, MethodReference reference, ClassHierarchy hierarchy,
-            WasmGCMethodReturnTypes returnTypes) {
+    public PreciseTypeInference(Program program, MethodReference reference, ClassHierarchy hierarchy) {
         super(program, reference);
         this.hierarchy = hierarchy;
-        this.returnTypes = returnTypes;
     }
 
     @Override
@@ -108,14 +104,6 @@ public class PreciseTypeInference extends BaseTypeInference<PreciseValueType> {
         return new PreciseValueType(ValueType.arrayOf(preciseValueType.valueType), false);
     }
 
-    @Override
-    protected PreciseValueType methodReturnType(InvocationType invocationType, MethodReference methodRef) {
-        if (invocationType == InvocationType.SPECIAL) {
-            return new PreciseValueType(returnTypes.returnTypeOf(methodRef), false);
-        }
-        return super.methodReturnType(invocationType, methodRef);
-    }
-
     @Override
     protected PreciseValueType arrayUnwrapType(PreciseValueType type) {
         return new PreciseValueType(type.valueType, true);
diff --git a/core/src/main/java/org/teavm/backend/wasm/gc/WasmGCMethodReturnTypes.java b/core/src/main/java/org/teavm/backend/wasm/gc/WasmGCMethodReturnTypes.java
deleted file mode 100644
index 4b9ce6fc3..000000000
--- a/core/src/main/java/org/teavm/backend/wasm/gc/WasmGCMethodReturnTypes.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- *  Copyright 2024 Alexey Andreev.
- *
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *       http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- */
-package org.teavm.backend.wasm.gc;
-
-import java.util.HashMap;
-import java.util.Map;
-import org.teavm.dependency.DependencyInfo;
-import org.teavm.model.ClassHierarchy;
-import org.teavm.model.MethodReference;
-import org.teavm.model.ValueType;
-
-public class WasmGCMethodReturnTypes {
-    private DependencyInfo dependencyInfo;
-    private ClassHierarchy hierarchy;
-    private Map<MethodReference, ValueType> cache = new HashMap<>();
-
-    public WasmGCMethodReturnTypes(DependencyInfo dependencyInfo, ClassHierarchy hierarchy) {
-        this.dependencyInfo = dependencyInfo;
-        this.hierarchy = hierarchy;
-    }
-
-    public ValueType returnTypeOf(MethodReference reference) {
-        return cache.computeIfAbsent(reference, this::calculateReturnType);
-    }
-
-    private ValueType calculateReturnType(MethodReference reference) {
-        if (!(reference.getReturnType() instanceof ValueType.Object)) {
-            return reference.getReturnType();
-        }
-        var method = dependencyInfo.getMethod(reference);
-        if (method == null) {
-            return reference.getReturnType();
-        }
-        var types = method.getResult().getTypes();
-        if (types.length == 0) {
-            return reference.getReturnType();
-        }
-        var type = hierarchy.getClassSource().get(types[0]);
-        if (type == null) {
-            return reference.getReturnType();
-        }
-        for (var i = 1; i < types.length; ++i) {
-            var otherType = hierarchy.getClassSource().get(types[i]);
-            if (otherType == null) {
-                return reference.getReturnType();
-            }
-            type = hierarchy.getClassSource().get(WasmGCUtil.findCommonSuperclass(hierarchy, type, otherType));
-        }
-        return ValueType.object(type.getName());
-    }
-}
diff --git a/core/src/main/java/org/teavm/backend/wasm/gc/WasmGCVariableCategoryProvider.java b/core/src/main/java/org/teavm/backend/wasm/gc/WasmGCVariableCategoryProvider.java
index 08060e4e6..b77560eae 100644
--- a/core/src/main/java/org/teavm/backend/wasm/gc/WasmGCVariableCategoryProvider.java
+++ b/core/src/main/java/org/teavm/backend/wasm/gc/WasmGCVariableCategoryProvider.java
@@ -23,11 +23,9 @@ import org.teavm.model.util.VariableCategoryProvider;
 public class WasmGCVariableCategoryProvider implements VariableCategoryProvider {
     private ClassHierarchy hierarchy;
     private PreciseTypeInference inference;
-    private WasmGCMethodReturnTypes returnTypes;
 
-    public WasmGCVariableCategoryProvider(ClassHierarchy hierarchy, WasmGCMethodReturnTypes returnTypes) {
+    public WasmGCVariableCategoryProvider(ClassHierarchy hierarchy) {
         this.hierarchy = hierarchy;
-        this.returnTypes = returnTypes;
     }
 
     public PreciseTypeInference getTypeInference() {
@@ -36,7 +34,7 @@ public class WasmGCVariableCategoryProvider implements VariableCategoryProvider
 
     @Override
     public Object[] getCategories(Program program, MethodReference method) {
-        inference = new PreciseTypeInference(program, method, hierarchy, returnTypes);
+        inference = new PreciseTypeInference(program, method, hierarchy);
         inference.setPhisSkipped(true);
         inference.setBackPropagation(true);
         var result = new Object[program.variableCount()];
diff --git a/core/src/main/java/org/teavm/backend/wasm/generate/common/methods/BaseWasmGenerationVisitor.java b/core/src/main/java/org/teavm/backend/wasm/generate/common/methods/BaseWasmGenerationVisitor.java
index 4d1cbe762..14cac5530 100644
--- a/core/src/main/java/org/teavm/backend/wasm/generate/common/methods/BaseWasmGenerationVisitor.java
+++ b/core/src/main/java/org/teavm/backend/wasm/generate/common/methods/BaseWasmGenerationVisitor.java
@@ -1170,6 +1170,11 @@ public abstract class BaseWasmGenerationVisitor implements StatementVisitor, Exp
 
     @Override
     public void visit(CastExpr expr) {
+        if (expr.isWeak()) {
+            acceptWithType(expr.getValue(), expr.getTarget());
+            result = generateCast(result, mapType(expr.getTarget()));
+            return;
+        }
         var block = new WasmBlock(false);
         var wasmTargetType = mapType(expr.getTarget());
         block.setType(wasmTargetType);
diff --git a/core/src/main/java/org/teavm/backend/wasm/generate/gc/WasmGCDeclarationsGenerator.java b/core/src/main/java/org/teavm/backend/wasm/generate/gc/WasmGCDeclarationsGenerator.java
index 4d8d6463c..b93f05dbf 100644
--- a/core/src/main/java/org/teavm/backend/wasm/generate/gc/WasmGCDeclarationsGenerator.java
+++ b/core/src/main/java/org/teavm/backend/wasm/generate/gc/WasmGCDeclarationsGenerator.java
@@ -19,7 +19,6 @@ import java.util.List;
 import java.util.function.Predicate;
 import org.teavm.backend.wasm.BaseWasmFunctionRepository;
 import org.teavm.backend.wasm.WasmFunctionTypes;
-import org.teavm.backend.wasm.gc.WasmGCMethodReturnTypes;
 import org.teavm.backend.wasm.generate.WasmNameProvider;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCClassGenerator;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCClassInfoProvider;
@@ -47,7 +46,6 @@ public class WasmGCDeclarationsGenerator {
     public final WasmFunctionTypes functionTypes;
     private final WasmGCClassGenerator classGenerator;
     private final WasmGCMethodGenerator methodGenerator;
-    private final WasmGCMethodReturnTypes returnTypes;
 
     public WasmGCDeclarationsGenerator(
             WasmModule module,
@@ -64,7 +62,6 @@ public class WasmGCDeclarationsGenerator {
         var virtualTables = createVirtualTableProvider(classes, virtualMethods);
         functionTypes = new WasmFunctionTypes(module);
         var names = new WasmNameProvider();
-        returnTypes = new WasmGCMethodReturnTypes(dependencyInfo, hierarchy);
         methodGenerator = new WasmGCMethodGenerator(
                 module,
                 hierarchy,
@@ -74,7 +71,6 @@ public class WasmGCDeclarationsGenerator {
                 functionTypes,
                 names,
                 diagnostics,
-                returnTypes,
                 customGenerators,
                 intrinsics
         );
diff --git a/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCGenerationContext.java b/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCGenerationContext.java
index 871374562..fcb901f0a 100644
--- a/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCGenerationContext.java
+++ b/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCGenerationContext.java
@@ -23,7 +23,6 @@ import java.util.Map;
 import java.util.Set;
 import org.teavm.backend.wasm.BaseWasmFunctionRepository;
 import org.teavm.backend.wasm.WasmFunctionTypes;
-import org.teavm.backend.wasm.gc.WasmGCMethodReturnTypes;
 import org.teavm.backend.wasm.generate.common.methods.BaseWasmGenerationContext;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCClassInfoProvider;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCStandardClasses;
@@ -57,7 +56,6 @@ public class WasmGCGenerationContext implements BaseWasmGenerationContext {
     private WasmGCSupertypeFunctionProvider supertypeFunctions;
     private WasmGCCustomGeneratorProvider customGenerators;
     private WasmGCIntrinsicProvider intrinsics;
-    private WasmGCMethodReturnTypes returnTypes;
     private WasmFunction npeMethod;
     private WasmFunction aaiobeMethod;
     private WasmFunction cceMethod;
@@ -70,8 +68,7 @@ public class WasmGCGenerationContext implements BaseWasmGenerationContext {
             ClassHierarchy hierarchy, BaseWasmFunctionRepository functions,
             WasmGCSupertypeFunctionProvider supertypeFunctions, WasmGCClassInfoProvider classInfoProvider,
             WasmGCStandardClasses standardClasses, WasmGCStringProvider strings,
-            WasmGCCustomGeneratorProvider customGenerators, WasmGCIntrinsicProvider intrinsics,
-            WasmGCMethodReturnTypes returnTypes) {
+            WasmGCCustomGeneratorProvider customGenerators, WasmGCIntrinsicProvider intrinsics) {
         this.module = module;
         this.virtualTables = virtualTables;
         this.typeMapper = typeMapper;
@@ -85,7 +82,6 @@ public class WasmGCGenerationContext implements BaseWasmGenerationContext {
         this.strings = strings;
         this.customGenerators = customGenerators;
         this.intrinsics = intrinsics;
-        this.returnTypes = returnTypes;
     }
 
     public WasmGCClassInfoProvider classInfoProvider() {
@@ -186,10 +182,6 @@ public class WasmGCGenerationContext implements BaseWasmGenerationContext {
         return intrinsics;
     }
 
-    public WasmGCMethodReturnTypes returnTypes() {
-        return returnTypes;
-    }
-
     public Collection<String> getInterfaceImplementors(String className) {
         if (interfaceImplementors == null) {
             fillInterfaceImplementors();
diff --git a/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCGenerationVisitor.java b/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCGenerationVisitor.java
index 5fad8f228..9237d5a92 100644
--- a/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCGenerationVisitor.java
+++ b/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCGenerationVisitor.java
@@ -481,7 +481,7 @@ public class WasmGCGenerationVisitor extends BaseWasmGenerationVisitor {
 
     @Override
     protected WasmExpression forceType(WasmExpression expression, ValueType type) {
-        return forceType(expression, mapType(context.returnTypes().returnTypeOf(currentMethod)));
+        return forceType(expression, mapType(currentMethod.getReturnType()));
     }
 
     private WasmExpression forceType(WasmExpression expression, WasmType expectedType) {
diff --git a/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCMethodGenerator.java b/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCMethodGenerator.java
index 78e53a167..7c7051912 100644
--- a/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCMethodGenerator.java
+++ b/core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCMethodGenerator.java
@@ -25,7 +25,6 @@ import org.teavm.ast.decompilation.Decompiler;
 import org.teavm.backend.lowlevel.generate.NameProvider;
 import org.teavm.backend.wasm.BaseWasmFunctionRepository;
 import org.teavm.backend.wasm.WasmFunctionTypes;
-import org.teavm.backend.wasm.gc.WasmGCMethodReturnTypes;
 import org.teavm.backend.wasm.gc.WasmGCVariableCategoryProvider;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCClassInfoProvider;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCStandardClasses;
@@ -78,7 +77,6 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
     private WasmGCClassInfoProvider classInfoProvider;
     private WasmGCStandardClasses standardClasses;
     private WasmGCStringProvider strings;
-    private WasmGCMethodReturnTypes returnTypes;
 
     public WasmGCMethodGenerator(
             WasmModule module,
@@ -89,7 +87,6 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
             WasmFunctionTypes functionTypes,
             NameProvider names,
             Diagnostics diagnostics,
-            WasmGCMethodReturnTypes returnTypes,
             WasmGCCustomGeneratorProvider customGenerators,
             WasmGCIntrinsicProvider intrinsics
     ) {
@@ -101,7 +98,6 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
         this.functionTypes = functionTypes;
         this.names = names;
         this.diagnostics = diagnostics;
-        this.returnTypes = returnTypes;
         this.customGenerators = customGenerators;
         this.intrinsics = intrinsics;
     }
@@ -146,7 +142,7 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
     }
 
     private WasmFunction createStaticFunction(MethodReference methodReference) {
-        var returnType = typeMapper.mapType(returnTypes.returnTypeOf(methodReference));
+        var returnType = typeMapper.mapType(methodReference.getReturnType());
         var parameterTypes = new WasmType[methodReference.parameterCount()];
         for (var i = 0; i < parameterTypes.length; ++i) {
             parameterTypes[i] = typeMapper.mapType(methodReference.parameterType(i));
@@ -173,7 +169,7 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
     }
 
     private WasmFunction createInstanceFunction(MethodReference methodReference) {
-        var returnType = typeMapper.mapType(returnTypes.returnTypeOf(methodReference));
+        var returnType = typeMapper.mapType(methodReference.getReturnType());
         var parameterTypes = new WasmType[methodReference.parameterCount() + 1];
         parameterTypes[0] = typeMapper.mapType(ValueType.object(methodReference.getClassName()));
         for (var i = 0; i < methodReference.parameterCount(); ++i) {
@@ -213,7 +209,7 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
 
     private void generateRegularMethodBody(MethodHolder method, WasmFunction function) {
         var decompiler = getDecompiler();
-        var categoryProvider = new WasmGCVariableCategoryProvider(hierarchy, returnTypes);
+        var categoryProvider = new WasmGCVariableCategoryProvider(hierarchy);
         var allocator = new RegisterAllocator(categoryProvider);
         allocator.allocateRegisters(method.getReference(), method.getProgram(), friendlyToDebugger);
         var ast = decompiler.decompileRegular(method);
@@ -302,8 +298,7 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
                     standardClasses,
                     strings,
                     customGenerators,
-                    intrinsics,
-                    returnTypes
+                    intrinsics
             );
         }
         return context;
diff --git a/core/src/main/java/org/teavm/cache/AstIO.java b/core/src/main/java/org/teavm/cache/AstIO.java
index 8139a047e..fb01c74e1 100644
--- a/core/src/main/java/org/teavm/cache/AstIO.java
+++ b/core/src/main/java/org/teavm/cache/AstIO.java
@@ -714,6 +714,7 @@ public class AstIO {
                 output.writeUnsigned(23);
                 output.writeUnsigned(symbolTable.lookup(expr.getTarget().toString()));
                 writeExpr(expr.getValue());
+                output.writeUnsigned(expr.isWeak() ? 1 : 0);
             } catch (IOException e) {
                 throw new IOExceptionWrapper(e);
             }
@@ -1106,6 +1107,7 @@ public class AstIO {
                 expr.setLocation(lastReadLocation);
                 expr.setTarget(ValueType.parse(symbolTable.at(input.readUnsigned())));
                 expr.setValue(readExpr(input));
+                expr.setWeak(input.readUnsigned() != 0);
                 return expr;
             }
             case 24: {
diff --git a/core/src/main/java/org/teavm/cache/ProgramIO.java b/core/src/main/java/org/teavm/cache/ProgramIO.java
index 42d5d1655..efdf974e2 100644
--- a/core/src/main/java/org/teavm/cache/ProgramIO.java
+++ b/core/src/main/java/org/teavm/cache/ProgramIO.java
@@ -451,12 +451,13 @@ public class ProgramIO {
         }
 
         @Override
-        public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
+        public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
             try {
                 output.writeUnsigned(25);
                 output.writeUnsigned(receiver.getIndex());
                 output.writeUnsigned(symbolTable.lookup(targetType.toString()));
                 output.writeUnsigned(value.getIndex());
+                output.writeUnsigned(weak ? 1 : 0);
             } catch (IOException e) {
                 throw new IOExceptionWrapper(e);
             }
@@ -988,6 +989,7 @@ public class ProgramIO {
                 insn.setReceiver(program.variableAt(input.readUnsigned()));
                 insn.setTargetType(parseValueType(symbolTable.at(input.readUnsigned())));
                 insn.setValue(program.variableAt(input.readUnsigned()));
+                insn.setWeak(input.readUnsigned() != 0);
                 return insn;
             }
             case 26: {
diff --git a/core/src/main/java/org/teavm/dependency/AbstractInstructionAnalyzer.java b/core/src/main/java/org/teavm/dependency/AbstractInstructionAnalyzer.java
index 88e2f55d8..0d1656247 100644
--- a/core/src/main/java/org/teavm/dependency/AbstractInstructionAnalyzer.java
+++ b/core/src/main/java/org/teavm/dependency/AbstractInstructionAnalyzer.java
@@ -228,12 +228,14 @@ abstract class AbstractInstructionAnalyzer extends AbstractInstructionReader {
     }
 
     @Override
-    public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
-        String className = extractClassName(targetType);
-        if (className != null) {
-            getAnalyzer().linkClass(className);
+    public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
+        if (!weak) {
+            String className = extractClassName(targetType);
+            if (className != null) {
+                getAnalyzer().linkClass(className);
+            }
+            getAnalyzer().linkClass("java.lang.ClassCastException");
         }
-        getAnalyzer().linkClass("java.lang.ClassCastException");
     }
 
     @Override
diff --git a/core/src/main/java/org/teavm/dependency/ClassClosureAnalyzer.java b/core/src/main/java/org/teavm/dependency/ClassClosureAnalyzer.java
index e5cdb1967..d7e68b11b 100644
--- a/core/src/main/java/org/teavm/dependency/ClassClosureAnalyzer.java
+++ b/core/src/main/java/org/teavm/dependency/ClassClosureAnalyzer.java
@@ -95,7 +95,7 @@ class ClassClosureAnalyzer extends AbstractInstructionReader {
     }
 
     @Override
-    public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
+    public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
         build(targetType);
     }
 
diff --git a/core/src/main/java/org/teavm/dependency/DataFlowGraphBuilder.java b/core/src/main/java/org/teavm/dependency/DataFlowGraphBuilder.java
index 66acf24db..421c714f3 100644
--- a/core/src/main/java/org/teavm/dependency/DataFlowGraphBuilder.java
+++ b/core/src/main/java/org/teavm/dependency/DataFlowGraphBuilder.java
@@ -143,7 +143,7 @@ public class DataFlowGraphBuilder extends AbstractInstructionReader {
     }
 
     @Override
-    public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
+    public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
         builder.addEdge(value.getIndex(), receiver.getIndex());
     }
 
diff --git a/core/src/main/java/org/teavm/dependency/DependencyGraphBuilder.java b/core/src/main/java/org/teavm/dependency/DependencyGraphBuilder.java
index 15c8c0579..0be2cdc14 100644
--- a/core/src/main/java/org/teavm/dependency/DependencyGraphBuilder.java
+++ b/core/src/main/java/org/teavm/dependency/DependencyGraphBuilder.java
@@ -221,9 +221,11 @@ class DependencyGraphBuilder {
         }
 
         @Override
-        public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
-            super.cast(receiver, value, targetType);
-            currentExceptionConsumer.consume(dependencyAnalyzer.getType("java.lang.ClassCastException"));
+        public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
+            super.cast(receiver, value, targetType, weak);
+            if (!weak) {
+                currentExceptionConsumer.consume(dependencyAnalyzer.getType("java.lang.ClassCastException"));
+            }
             DependencyNode valueNode = nodes[value.getIndex()];
             DependencyNode receiverNode = nodes[receiver.getIndex()];
             ClassReaderSource classSource = dependencyAnalyzer.getClassSource();
diff --git a/core/src/main/java/org/teavm/model/InstructionReadVisitor.java b/core/src/main/java/org/teavm/model/InstructionReadVisitor.java
index b7a1da1a7..c6e0649d2 100644
--- a/core/src/main/java/org/teavm/model/InstructionReadVisitor.java
+++ b/core/src/main/java/org/teavm/model/InstructionReadVisitor.java
@@ -83,7 +83,7 @@ public class InstructionReadVisitor implements InstructionVisitor {
 
     @Override
     public void visit(CastInstruction insn) {
-        reader.cast(insn.getReceiver(), insn.getValue(), insn.getTargetType());
+        reader.cast(insn.getReceiver(), insn.getValue(), insn.getTargetType(), insn.isWeak());
     }
 
     @Override
diff --git a/core/src/main/java/org/teavm/model/Interpreter.java b/core/src/main/java/org/teavm/model/Interpreter.java
index dbe087d8e..b72aa0162 100644
--- a/core/src/main/java/org/teavm/model/Interpreter.java
+++ b/core/src/main/java/org/teavm/model/Interpreter.java
@@ -340,7 +340,7 @@ public class Interpreter {
         }
 
         @Override
-        public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
+        public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean cast) {
             variables[receiver.getIndex()] = asJvmClass(targetType).cast(variables[value.getIndex()]);
         }
 
diff --git a/core/src/main/java/org/teavm/model/instructions/AbstractInstructionReader.java b/core/src/main/java/org/teavm/model/instructions/AbstractInstructionReader.java
index 942c739ee..2919d4056 100644
--- a/core/src/main/java/org/teavm/model/instructions/AbstractInstructionReader.java
+++ b/core/src/main/java/org/teavm/model/instructions/AbstractInstructionReader.java
@@ -77,7 +77,7 @@ public class AbstractInstructionReader implements InstructionReader {
     }
 
     @Override
-    public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
+    public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
     }
 
     @Override
diff --git a/core/src/main/java/org/teavm/model/instructions/CastInstruction.java b/core/src/main/java/org/teavm/model/instructions/CastInstruction.java
index 9e91d93af..a06b2f7e0 100644
--- a/core/src/main/java/org/teavm/model/instructions/CastInstruction.java
+++ b/core/src/main/java/org/teavm/model/instructions/CastInstruction.java
@@ -23,6 +23,7 @@ public class CastInstruction extends Instruction {
     private Variable value;
     private Variable receiver;
     private ValueType targetType;
+    private boolean weak;
 
     public Variable getValue() {
         return value;
@@ -48,6 +49,14 @@ public class CastInstruction extends Instruction {
         this.targetType = targetType;
     }
 
+    public boolean isWeak() {
+        return weak;
+    }
+
+    public void setWeak(boolean weak) {
+        this.weak = weak;
+    }
+
     @Override
     public void acceptVisitor(InstructionVisitor visitor) {
         visitor.visit(this);
diff --git a/core/src/main/java/org/teavm/model/instructions/InstructionReader.java b/core/src/main/java/org/teavm/model/instructions/InstructionReader.java
index 8991ef290..405126ab3 100644
--- a/core/src/main/java/org/teavm/model/instructions/InstructionReader.java
+++ b/core/src/main/java/org/teavm/model/instructions/InstructionReader.java
@@ -44,7 +44,7 @@ public interface InstructionReader {
 
     void assign(VariableReader receiver, VariableReader assignee);
 
-    void cast(VariableReader receiver, VariableReader value, ValueType targetType);
+    void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak);
 
     void cast(VariableReader receiver, VariableReader value, NumericOperandType sourceType,
             NumericOperandType targetType);
diff --git a/core/src/main/java/org/teavm/model/lowlevel/ExceptionHandlingUtil.java b/core/src/main/java/org/teavm/model/lowlevel/ExceptionHandlingUtil.java
index ec75dc9b9..73708bd99 100644
--- a/core/src/main/java/org/teavm/model/lowlevel/ExceptionHandlingUtil.java
+++ b/core/src/main/java/org/teavm/model/lowlevel/ExceptionHandlingUtil.java
@@ -43,9 +43,10 @@ public final class ExceptionHandlingUtil {
                 || insn instanceof ConstructArrayInstruction || insn instanceof ConstructMultiArrayInstruction
                 || insn instanceof CloneArrayInstruction || insn instanceof RaiseInstruction
                 || insn instanceof MonitorEnterInstruction || insn instanceof MonitorExitInstruction
-                || insn instanceof NullCheckInstruction || insn instanceof BoundCheckInstruction
-                || insn instanceof CastInstruction) {
+                || insn instanceof NullCheckInstruction || insn instanceof BoundCheckInstruction) {
             return true;
+        } else if (insn instanceof CastInstruction) {
+            return !((CastInstruction) insn).isWeak();
         } else if (insn instanceof InvokeInstruction) {
             return isManagedMethodCall(characteristics, ((InvokeInstruction) insn).getMethod());
         }
diff --git a/core/src/main/java/org/teavm/model/lowlevel/NativePointerFinder.java b/core/src/main/java/org/teavm/model/lowlevel/NativePointerFinder.java
index 176e57968..c0ad41251 100644
--- a/core/src/main/java/org/teavm/model/lowlevel/NativePointerFinder.java
+++ b/core/src/main/java/org/teavm/model/lowlevel/NativePointerFinder.java
@@ -93,7 +93,7 @@ public class NativePointerFinder {
         }
 
         @Override
-        public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
+        public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
             assignmentGraph.addEdge(value.getIndex(), receiver.getIndex());
         }
 
diff --git a/core/src/main/java/org/teavm/model/optimization/Devirtualization.java b/core/src/main/java/org/teavm/model/optimization/Devirtualization.java
index 62f6e2616..f6672a1c2 100644
--- a/core/src/main/java/org/teavm/model/optimization/Devirtualization.java
+++ b/core/src/main/java/org/teavm/model/optimization/Devirtualization.java
@@ -31,7 +31,6 @@ import org.teavm.model.MethodHolder;
 import org.teavm.model.MethodReference;
 import org.teavm.model.Program;
 import org.teavm.model.ValueType;
-import org.teavm.model.instructions.AssignInstruction;
 import org.teavm.model.instructions.CastInstruction;
 import org.teavm.model.instructions.InvocationType;
 import org.teavm.model.instructions.InvokeInstruction;
@@ -172,11 +171,7 @@ public class Devirtualization {
                 }
                 System.out.println();
             }
-            AssignInstruction assign = new AssignInstruction();
-            assign.setAssignee(cast.getValue());
-            assign.setReceiver(cast.getReceiver());
-            assign.setLocation(cast.getLocation());
-            cast.replace(assign);
+            cast.setWeak(true);
             eliminatedCasts++;
         }
     }
diff --git a/core/src/main/java/org/teavm/model/optimization/GlobalValueNumbering.java b/core/src/main/java/org/teavm/model/optimization/GlobalValueNumbering.java
index f9899f9b1..86cf03e2a 100644
--- a/core/src/main/java/org/teavm/model/optimization/GlobalValueNumbering.java
+++ b/core/src/main/java/org/teavm/model/optimization/GlobalValueNumbering.java
@@ -570,7 +570,8 @@ public class GlobalValueNumbering implements MethodOptimization {
             int a = map[insn.getValue().getIndex()];
             int p = replaceMap[insn.getValue().getIndex()];
             insn.setValue(program.variableAt(p));
-            bind(insn.getReceiver().getIndex(), "@" + a + "::" + insn.getTargetType());
+            var operator = insn.isWeak() ? ":::" : "::";
+            bind(insn.getReceiver().getIndex(), "@" + a + operator + insn.getTargetType());
         }
 
         @Override
diff --git a/core/src/main/java/org/teavm/model/text/InstructionStringifier.java b/core/src/main/java/org/teavm/model/text/InstructionStringifier.java
index 0dc8b3fd5..f908689dc 100644
--- a/core/src/main/java/org/teavm/model/text/InstructionStringifier.java
+++ b/core/src/main/java/org/teavm/model/text/InstructionStringifier.java
@@ -240,8 +240,12 @@ class InstructionStringifier implements InstructionReader {
     }
 
     @Override
-    public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
-        appendLocalVar(receiver).append(" := cast ").appendLocalVar(value).append(" to ")
+    public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
+        appendLocalVar(receiver).append(" := ");
+        if (weak) {
+            append("weak ");
+        }
+        append("cast ").appendLocalVar(value).append(" to ")
                 .escapeIdentifierIfNeeded(targetType.toString());
     }
 
diff --git a/core/src/main/java/org/teavm/model/util/InstructionCopyReader.java b/core/src/main/java/org/teavm/model/util/InstructionCopyReader.java
index 0474c3023..881f6c1df 100644
--- a/core/src/main/java/org/teavm/model/util/InstructionCopyReader.java
+++ b/core/src/main/java/org/teavm/model/util/InstructionCopyReader.java
@@ -208,11 +208,12 @@ public class InstructionCopyReader implements InstructionReader {
     }
 
     @Override
-    public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
+    public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
         CastInstruction insnCopy = new CastInstruction();
         insnCopy.setValue(copyVar(value));
         insnCopy.setReceiver(copyVar(receiver));
         insnCopy.setTargetType(targetType);
+        insnCopy.setWeak(weak);
         copy = insnCopy;
         copy.setLocation(location);
     }
diff --git a/core/src/main/java/org/teavm/model/util/TypeInferer.java b/core/src/main/java/org/teavm/model/util/TypeInferer.java
index a9c59d8b7..434a30e01 100644
--- a/core/src/main/java/org/teavm/model/util/TypeInferer.java
+++ b/core/src/main/java/org/teavm/model/util/TypeInferer.java
@@ -296,7 +296,7 @@ public class TypeInferer {
         }
 
         @Override
-        public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
+        public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
             types[receiver.getIndex()] = convert(targetType);
         }
 
diff --git a/jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java b/jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java
index 472e104f9..f072060dc 100644
--- a/jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java
+++ b/jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java
@@ -465,6 +465,9 @@ class JSClassProcessor {
     }
 
     private boolean processCast(CastInstruction cast, CallLocation location) {
+        if (cast.isWeak()) {
+            return false;
+        }
         if (!(cast.getTargetType() instanceof ValueType.Object)) {
             cast.setTargetType(processType(cast.getTargetType()));
             return false;
diff --git a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/CompositeMethodGenerator.java b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/CompositeMethodGenerator.java
index ae9c10c4d..973774afc 100644
--- a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/CompositeMethodGenerator.java
+++ b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/CompositeMethodGenerator.java
@@ -607,7 +607,7 @@ public class CompositeMethodGenerator {
         }
 
         @Override
-        public void cast(VariableReader receiver, VariableReader value, ValueType targetType) {
+        public void cast(VariableReader receiver, VariableReader value, ValueType targetType, boolean weak) {
             CastInstruction insn = new CastInstruction();
             insn.setTargetType(targetType);
             insn.setValue(var(value));
diff --git a/platform/src/main/java/org/teavm/platform/plugin/ResourceProgramTransformer.java b/platform/src/main/java/org/teavm/platform/plugin/ResourceProgramTransformer.java
index 9b3f23f0f..be7101645 100644
--- a/platform/src/main/java/org/teavm/platform/plugin/ResourceProgramTransformer.java
+++ b/platform/src/main/java/org/teavm/platform/plugin/ResourceProgramTransformer.java
@@ -77,7 +77,7 @@ class ResourceProgramTransformer {
     }
 
     private void removeCastToResource(CastInstruction cast) {
-        if (hierarchy.isSuperType(RESOURCE, cast.getTargetType(), false)) {
+        if (!cast.isWeak() && hierarchy.isSuperType(RESOURCE, cast.getTargetType(), false)) {
             AssignInstruction assign = new AssignInstruction();
             assign.setReceiver(cast.getReceiver());
             assign.setAssignee(cast.getValue());