diff --git a/extra/tools/vocabs/vocabs-tests.factor b/extra/tools/vocabs/vocabs-tests.factor
new file mode 100644
index 0000000000..ae74d516e4
--- /dev/null
+++ b/extra/tools/vocabs/vocabs-tests.factor
@@ -0,0 +1,8 @@
+IN: tools.vocabs.tests
+USING: tools.test tools.vocabs namespaces continuations ;
+
+[ ] [
+    changed-vocabs get-global
+    f changed-vocabs set-global
+    [ "kernel" changed-vocab ] [ changed-vocabs set-global ] [ ] cleanup
+] unit-test
diff --git a/extra/tools/vocabs/vocabs.factor b/extra/tools/vocabs/vocabs.factor
index 211b396c50..371bbc7813 100755
--- a/extra/tools/vocabs/vocabs.factor
+++ b/extra/tools/vocabs/vocabs.factor
@@ -76,11 +76,11 @@ SYMBOL: changed-vocabs
 [ f changed-vocabs set-global ] "tools.vocabs" add-init-hook
 
 : changed-vocab ( vocab -- )
-    dup vocab
-    [ dup changed-vocabs get-global set-at ] [ drop ] if ;
+    dup vocab changed-vocabs get and
+    [ dup changed-vocabs get set-at ] [ drop ] if ;
 
 : unchanged-vocab ( vocab -- )
-    changed-vocabs get-global delete-at ;
+    changed-vocabs get delete-at ;
 
 : unchanged-vocabs ( vocabs -- )
     [ unchanged-vocab ] each ;