diff --git a/assemble.rkt b/assemble.rkt
index 8884d48..c2ddcbc 100644
--- a/assemble.rkt
+++ b/assemble.rkt
@@ -26,8 +26,8 @@
                        (displayln (assemble-basic-block basic-block) op)
                        (newline op))
               basic-blocks)
-    (fprintf op "MACHINE.params.currentErrorHandler = function(e) { fail(e); };\n")
-    (fprintf op "MACHINE.params.currentSuccessHandler = function(MACHINE) { success(MACHINE.val); };\n")
+    (fprintf op "MACHINE.params.currentErrorHandler = fail;\n")
+    (fprintf op "MACHINE.params.currentSuccessHandler = success;\n")
     (fprintf op #<<EOF
 for (param in params) {
     if (params.hasOwnProperty(param)) {
diff --git a/runtime.js b/runtime.js
index b6e8660..8a9aa5d 100644
--- a/runtime.js
+++ b/runtime.js
@@ -309,8 +309,8 @@ var MACHINE = { callsBeforeTrampoline: 100,
 		running : false,
 		params: { currentDisplayer: function(v) {},
 
-			  currentSuccessHandler: function(v) {},
-			  currentErrorHandler: function(e) {},
+			  currentSuccessHandler: function(MACHINE) {},
+			  currentErrorHandler: function(MACHINE, exn) {},
 
 			  currentNamespace: {},
 
@@ -379,7 +379,7 @@ var trampoline = function(MACHINE, initialJump) {
 		}
             } else {
 		MACHINE.running = false;
-	        return MACHINE.params.currentErrorHandler(e);
+	        return MACHINE.params.currentErrorHandler(MACHINE, e);
             }
         }
     }