diff --git a/assemble-open-coded.rkt b/assemble-open-coded.rkt
index b158891..91c605e 100644
--- a/assemble-open-coded.rkt
+++ b/assemble-open-coded.rkt
@@ -89,7 +89,7 @@
            (format "(~a === RUNTIME.NULL)" (first checked-operands))]
 
           [(not)
-           (format "(!(~a))" (first checked-operands))]
+           (format "(~a === false)" (first checked-operands))]
           
           [(eq?)
            (format "(~a === ~a)" (first checked-operands) (second checked-operands))])))
diff --git a/runtime.js b/runtime.js
index 0e9fda4..004cec8 100644
--- a/runtime.js
+++ b/runtime.js
@@ -687,7 +687,7 @@
     
     Primitives['not'] = function(MACHINE) {
 	var firstArg = MACHINE.env[MACHINE.env.length-1];
-	return (!firstArg);
+	return (firstArg === false);
     };
     Primitives['not'].arity = 1;
     Primitives['not'].displayName = 'not';
diff --git a/test-browser-evaluate.rkt b/test-browser-evaluate.rkt
index 1b3c6c6..502397a 100644
--- a/test-browser-evaluate.rkt
+++ b/test-browser-evaluate.rkt
@@ -141,6 +141,10 @@ EOF
 (test '(displayln (not (not 3)))
       "true\n")
 
+(test '(displayln (not 0))
+      "false\n")
+
+
 (test '(displayln (add1 1))
       "2\n")