diff --git a/extra/sequences/extras/extras.factor b/extra/sequences/extras/extras.factor
index a515a9dba5..6805f7a268 100644
--- a/extra/sequences/extras/extras.factor
+++ b/extra/sequences/extras/extras.factor
@@ -119,9 +119,9 @@ IN: sequences.extras
     cut prepend ;
 
 :: rotate! ( seq n -- )
-    seq length :> end
-    n 0 n [ 2dup = ] [
-        [ seq exchange ] [ [ 1 + ] bi@ ] 2bi
+    n seq bounds-check length :> end
+    0 n [ 2dup = ] [
+        [ seq exchange-unsafe ] [ [ 1 + ] bi@ ] 2bi
         dup end = [ drop over ] when
         2over = [ -rot nip over ] when
     ] until 3drop ;