diff --git a/nixos/doc/manual/Makefile b/nixos/doc/manual/Makefile
index 4993976ae57e..2e2322d5fb51 100644
--- a/nixos/doc/manual/Makefile
+++ b/nixos/doc/manual/Makefile
@@ -5,7 +5,7 @@ all: manual-combined.xml format
 debug: generated manual-combined.xml
 
 manual-combined.xml: generated *.xml
-	rm ./manual-combined.xml
+	rm -f ./manual-combined.xml
 	nix-shell --packages xmloscopy \
 		--run "xmloscopy --docbook5 ./manual.xml ./manual-combined.xml"