diff --git a/src/buffer.c b/src/buffer.c
index d62e186fda8..403baa817d3 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -532,6 +532,7 @@ CLONE nil means the indirect buffer's state is reset to default values.  */)
   Lisp_Object buf;
   struct buffer *b;
 
+  CHECK_STRING (name);
   buf = Fget_buffer (name);
   if (!NILP (buf))
     error ("Buffer name `%s' is in use", SDATA (name));