diff --git a/cfb/cfb.h b/cfb/cfb.h
index e80a427ec..aece13341 100644
--- a/cfb/cfb.h
+++ b/cfb/cfb.h
@@ -81,6 +81,8 @@ typedef struct {
     CfbBits	xor, and;
 } cfbRRopRec, *cfbRRopPtr;
 
+/* cfb8bit.c */
+
 extern int cfbSetStipple(
     int /*alu*/,
     CfbBits /*fg*/,