diff --git a/core/src/main/java/org/teavm/backend/wasm/intrinsics/LongIntrinsic.java b/core/src/main/java/org/teavm/backend/wasm/intrinsics/LongIntrinsic.java
index a05771c67..6db12665b 100644
--- a/core/src/main/java/org/teavm/backend/wasm/intrinsics/LongIntrinsic.java
+++ b/core/src/main/java/org/teavm/backend/wasm/intrinsics/LongIntrinsic.java
@@ -16,6 +16,8 @@
 package org.teavm.backend.wasm.intrinsics;
 
 import org.teavm.ast.InvocationExpr;
+import org.teavm.backend.wasm.WasmRuntime;
+import org.teavm.backend.wasm.model.expression.WasmCall;
 import org.teavm.backend.wasm.model.expression.WasmExpression;
 import org.teavm.backend.wasm.model.expression.WasmIntBinary;
 import org.teavm.backend.wasm.model.expression.WasmIntBinaryOperation;
@@ -23,6 +25,9 @@ import org.teavm.backend.wasm.model.expression.WasmIntType;
 import org.teavm.model.MethodReference;
 
 public class LongIntrinsic implements WasmIntrinsic {
+    private static final MethodReference COMPARE_UNSIGNED = new MethodReference(WasmRuntime.class,
+            "compareUnsigned", long.class, long.class, int.class);
+
     @Override
     public boolean isApplicable(MethodReference methodReference) {
         if (!methodReference.getClassName().equals(Long.class.getName())) {
@@ -32,6 +37,7 @@ public class LongIntrinsic implements WasmIntrinsic {
         switch (methodReference.getName()) {
             case "divideUnsigned":
             case "remainderUnsigned":
+            case "compareUnsigned":
                 return true;
             default:
                 return false;
@@ -49,6 +55,10 @@ public class LongIntrinsic implements WasmIntrinsic {
                 return new WasmIntBinary(WasmIntType.INT64, WasmIntBinaryOperation.REM_UNSIGNED,
                         manager.generate(invocation.getArguments().get(0)),
                         manager.generate(invocation.getArguments().get(1)));
+            case "compareUnsigned":
+                return new WasmCall(manager.getNames().forMethod(COMPARE_UNSIGNED),
+                        manager.generate(invocation.getArguments().get(0)),
+                        manager.generate(invocation.getArguments().get(1)));
             default:
                 throw new AssertionError();
         }