diff -r 2d537f8cd604 -r 04e312a7887e vm/src/test/java/org/apidesign/vm4brwsr/NumberTest.java
--- a/vm/src/test/java/org/apidesign/vm4brwsr/NumberTest.java	Fri Feb 01 06:09:18 2013 +0100
+++ b/vm/src/test/java/org/apidesign/vm4brwsr/NumberTest.java	Fri Feb 01 09:00:30 2013 +0100
@@ -151,6 +151,24 @@
         );
     }
     
+    @Test public void longNegate1() throws Exception {
+        final long res = -0x00fa37d7763e0ca1l;
+        assertExec("Long negate",
+            Numbers.class, "negL__J_3B", 
+            Double.valueOf(res),
+                new byte[] { (byte)0x00, (byte)0xfa, (byte)0x37, (byte)0xd7, (byte)0x76, (byte)0x3e, (byte)0x0c, (byte)0xa1 }
+        );
+    }
+    
+    @Test public void longNegate2() throws Exception {
+        final long res = -0x80fa37d7763e0ca1l;
+        assertExec("Long negate",
+            Numbers.class, "negL__J_3B", 
+            Double.valueOf(res),
+                new byte[] { (byte)0x80, (byte)0xfa, (byte)0x37, (byte)0xd7, (byte)0x76, (byte)0x3e, (byte)0x0c, (byte)0xa1 }
+        );
+    }
+    
     @Test public void longAddOverflow() throws Exception {
         final long res = Long.MAX_VALUE + 1l;
         assertExec("Addition 1+MAX",