diff --git a/documentation/Makefile b/documentation/Makefile
index c5888bb4b..4f4cae0e7 100644
--- a/documentation/Makefile
+++ b/documentation/Makefile
@@ -72,7 +72,7 @@ dist:	all html pdf
 alldocs: dist
 
 clean:
-	$(RM) fltk.pdf
+	$(RM) fltk.pdf refman.pdf
 	$(RMDIR) html latex
 	$(RM) *~ *.bck *.bak *.log
 	$(RM) $(MANPAGES) $(SRC_DOCDIR)/*.0