diff --git a/Makefile.in b/Makefile.in
index 459b4727..159caadc 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -82,7 +82,7 @@ VERSION		=	@SVERSION@
 
 dmg:
 	echo Signing HTMLDOC application bundle
-	codesign -s "$(CODESIGN_IDENTITY)" --timestamp -o runtime htmldoc/htmldoc.app
+	codesign -f -s "$(CODESIGN_IDENTITY)" --timestamp -o runtime htmldoc/htmldoc.app
 	echo Creating archive for notarization
 	rm -f htmldoc/htmldoc.zip
 	ditto -c -k --keepParent htmldoc/htmldoc.app htmldoc/htmldoc.zip