diff --git a/lib/chibi/test.module b/lib/chibi/test.module
index d8b405f1..66e97d54 100644
--- a/lib/chibi/test.module
+++ b/lib/chibi/test.module
@@ -1,7 +1,7 @@
 
 (define-module (chibi test)
   (export
-   test test-error test-assert test-values
+   test test-error test-assert test-not test-values
    test-group current-test-group
    test-begin test-end test-syntax-error test-info
    test-vars test-run ;;test-exit
diff --git a/lib/chibi/test.scm b/lib/chibi/test.scm
index bfa7429e..39939e8c 100644
--- a/lib/chibi/test.scm
+++ b/lib/chibi/test.scm
@@ -80,6 +80,11 @@
      (test-syntax-error 'test-assert "1 or 2 arguments required"
                         (test a ...)))))
 
+(define-syntax test-not
+  (syntax-rules ()
+    ((_ expr) (test-assert (not expr)))
+    ((_ name expr) (test-assert name (not expr)))))
+
 (define-syntax test-values
   (syntax-rules ()
     ((_ expect expr)