diff --git a/src/de/inetsoftware/jwebassembly/module/TypeManager.java b/src/de/inetsoftware/jwebassembly/module/TypeManager.java
index 5795332..4989e6c 100644
--- a/src/de/inetsoftware/jwebassembly/module/TypeManager.java
+++ b/src/de/inetsoftware/jwebassembly/module/TypeManager.java
@@ -1206,6 +1206,17 @@ public class TypeManager {
         String getInterfaceMethodName() {
             return interfaceMethodName;
         }
+
+        /**
+         * {@inheritDoc}
+         */
+        @Override
+        public boolean isSubTypeOf( AnyType type ) {
+            if( type == this || type == ValueType.externref || type == ValueType.anyref || type == ValueType.eqref ) {
+                return true;
+            }
+            return type == interfaceType;
+        }
     }
 
     /**
diff --git a/src/de/inetsoftware/jwebassembly/wasm/ArrayType.java b/src/de/inetsoftware/jwebassembly/wasm/ArrayType.java
index 0c47728..719aa6d 100644
--- a/src/de/inetsoftware/jwebassembly/wasm/ArrayType.java
+++ b/src/de/inetsoftware/jwebassembly/wasm/ArrayType.java
@@ -167,6 +167,19 @@ public class ArrayType extends StructType {
      */
     @Override
     public boolean isSubTypeOf( AnyType type ) {
-        return type == this || type == ValueType.externref;
+        if( type == this || type == ValueType.externref ) {
+            return true;
+        }
+        if( !(type instanceof StructType) ) {
+            return false;
+        }
+        StructType structType = (StructType)type;
+        switch( structType.getKind() ) {
+            case normal:
+                return "java/lang/Object".equals( structType.getName() );
+            case array:
+                return arrayType.isSubTypeOf( ((ArrayType)structType).arrayType );
+        }
+        return false;
     }
 }
diff --git a/test/de/inetsoftware/jwebassembly/module/StructTypeTest.java b/test/de/inetsoftware/jwebassembly/module/StructTypeTest.java
index 262021f..a721c24 100644
--- a/test/de/inetsoftware/jwebassembly/module/StructTypeTest.java
+++ b/test/de/inetsoftware/jwebassembly/module/StructTypeTest.java
@@ -19,12 +19,14 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 
 import org.junit.Before;
 import org.junit.Test;
 
 import de.inetsoftware.jwebassembly.JWebAssembly;
+import de.inetsoftware.jwebassembly.module.TypeManager.LambdaType;
 import de.inetsoftware.jwebassembly.module.TypeManager.StructType;
 import de.inetsoftware.jwebassembly.module.TypeManager.StructTypeKind;
 
@@ -99,4 +101,12 @@ public class StructTypeTest {
         assertFalse( typeObjArray.isSubTypeOf( typeIntArray ) );
     }
 
+    @Test
+    public void isSubTypeOf_Lambda() throws Throwable {
+        StructType typeRunnable = manager.valueOf( "java/lang/Runnable" );
+        LambdaType lambda = manager.lambdaType( "typeName", new ArrayList(), typeRunnable, new FunctionName( "", "", "" ), "run" );
+
+        assertTrue( lambda.isSubTypeOf( typeRunnable ) );
+        assertFalse( typeRunnable.isSubTypeOf( lambda ) );
+    }
 }