diff --git a/core/src/main/java/org/teavm/backend/wasm/WasmTarget.java b/core/src/main/java/org/teavm/backend/wasm/WasmTarget.java
index 57e6a002c..f73e26ed6 100644
--- a/core/src/main/java/org/teavm/backend/wasm/WasmTarget.java
+++ b/core/src/main/java/org/teavm/backend/wasm/WasmTarget.java
@@ -66,6 +66,7 @@ import org.teavm.backend.wasm.model.expression.WasmLoadInt32;
 import org.teavm.backend.wasm.model.expression.WasmReturn;
 import org.teavm.backend.wasm.model.expression.WasmSetLocal;
 import org.teavm.backend.wasm.model.expression.WasmStoreInt32;
+import org.teavm.backend.wasm.optimization.UnusedFunctionElimination;
 import org.teavm.backend.wasm.patches.ClassPatch;
 import org.teavm.backend.wasm.render.WasmBinaryRenderer;
 import org.teavm.backend.wasm.render.WasmBinaryWriter;
@@ -338,6 +339,8 @@ public class WasmTarget implements TeaVMTarget {
             module.getFunctionTable().add(module.getFunctions().get(function));
         }
 
+        new UnusedFunctionElimination(module).apply();
+
         WasmBinaryWriter writer = new WasmBinaryWriter();
         WasmBinaryRenderer renderer = new WasmBinaryRenderer(writer);
         renderer.render(module);
diff --git a/core/src/main/java/org/teavm/backend/wasm/model/WasmModule.java b/core/src/main/java/org/teavm/backend/wasm/model/WasmModule.java
index e9de2dbe6..541812886 100644
--- a/core/src/main/java/org/teavm/backend/wasm/model/WasmModule.java
+++ b/core/src/main/java/org/teavm/backend/wasm/model/WasmModule.java
@@ -40,6 +40,14 @@ public class WasmModule {
         function.module = this;
     }
 
+    public void remove(WasmFunction function) {
+        if (function.getModule() != this) {
+            return;
+        }
+        function.module = null;
+        functions.remove(function.getName());
+    }
+
     public Map<String, WasmFunction> getFunctions() {
         return readonlyFunctions;
     }
diff --git a/core/src/main/java/org/teavm/backend/wasm/optimization/UnusedFunctionElimination.java b/core/src/main/java/org/teavm/backend/wasm/optimization/UnusedFunctionElimination.java
new file mode 100644
index 000000000..b0dc43d09
--- /dev/null
+++ b/core/src/main/java/org/teavm/backend/wasm/optimization/UnusedFunctionElimination.java
@@ -0,0 +1,77 @@
+/*
+ *  Copyright 2016 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.optimization;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import org.teavm.backend.wasm.model.WasmFunction;
+import org.teavm.backend.wasm.model.WasmModule;
+import org.teavm.backend.wasm.model.expression.WasmCall;
+import org.teavm.backend.wasm.model.expression.WasmDefaultExpressionVisitor;
+import org.teavm.backend.wasm.model.expression.WasmExpression;
+import org.teavm.backend.wasm.model.expression.WasmExpressionVisitor;
+
+public class UnusedFunctionElimination {
+    private WasmModule module;
+    private Set<WasmFunction> usedFunctions = new HashSet<>();
+
+    public UnusedFunctionElimination(WasmModule module) {
+        this.module = module;
+    }
+
+    public void apply() {
+        List<WasmFunction> exported = module.getFunctions().values().stream()
+                .filter(function -> function.getExportName() != null)
+                .collect(Collectors.toList());
+        for (WasmFunction function : exported) {
+            use(function);
+        }
+        for (WasmFunction function : module.getFunctionTable()) {
+            use(function);
+        }
+        if (module.getStartFunction() != null) {
+            use(module.getStartFunction());
+        }
+
+        for (WasmFunction function : module.getFunctions().values().toArray(new WasmFunction[0])) {
+            if (!usedFunctions.contains(function)) {
+                module.remove(function);
+            }
+        }
+    }
+
+    private void use(WasmFunction function) {
+        if (!usedFunctions.add(function)) {
+            return;
+        }
+        for (WasmExpression part : function.getBody()) {
+            part.acceptVisitor(visitor);
+        }
+    }
+
+    private WasmExpressionVisitor visitor = new WasmDefaultExpressionVisitor() {
+        @Override
+        public void visit(WasmCall expression) {
+            super.visit(expression);
+            WasmFunction function = module.getFunctions().get(expression.getFunctionName());
+            if (function != null) {
+                use(function);
+            }
+        }
+    };
+}