diff -r 189f695d0b02 -r 4c2b92281cdc vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java
--- a/vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java	Thu Jan 31 15:26:09 2013 +0100
+++ b/vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java	Thu Jan 31 20:19:38 2013 +0100
@@ -588,7 +588,7 @@
                     emit(out, "@1 |= @2;", smapper.getI(1), smapper.popI());
                     break;
                 case opc_lor:
-                    emit(out, "@1 |= @2;", smapper.getL(1), smapper.popL());
+                    emit(out, "@1 = @1.or64(@2);", smapper.getL(1), smapper.popL());
                     break;
                 case opc_ixor:
                     emit(out, "@1 ^= @2;", smapper.getI(1), smapper.popI());