diff --git a/Makefile b/Makefile
index d0f5c9785..0fcd7784f 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@
 # Various contributors (see AUTHORS.txt)
 # https://tuxpaint.org/
 
-# June 14, 2002 - April 30, 2023
+# June 14, 2002 - May 1, 2023
 
 
 # The version number, for release:
@@ -858,7 +858,7 @@ $(THUMB_STARTERS):
 		convert $(CONVERT_OPTS) obj/tmp_$(notdir $(STARTER_NAME)).png $@ 2> /dev/null ; \
 		rm obj/tmp_$(notdir $(STARTER_NAME)).png ; \
 	else \
-		convert $(CONVERT_OPTS) $(STARTER_NAME) $@ 2> /dev/null || ( echo "($@ failed)" ; rm $@ ) ; \
+		convert $(CONVERT_OPTS) $(STARTER_NAME) $@ 2> /dev/null || ( echo "($@ failed)" ; rm -f $@ ) ; \
 	fi
 
 $(INSTALLED_THUMB_STARTERS): $(DATA_PREFIX)/%: % install-example-starters-dirs
@@ -913,7 +913,7 @@ TEMPLATE_NAME=$(or $(wildcard $(subst templates/.thumbs,templates,$(@:-t.png=.sv
 $(THUMB_TEMPLATES):
 	@printf "."
 	@mkdir -p templates/.thumbs
-	@convert $(CONVERT_OPTS) $(TEMPLATE_NAME) $@ 2> /dev/null || ( echo "($@ failed)" ; rm $@ ) ; \
+	@convert $(CONVERT_OPTS) $(TEMPLATE_NAME) $@ 2> /dev/null || ( echo "($@ failed)" ; rm -f $@ ) ; \
 
 $(INSTALLED_THUMB_TEMPLATES): $(DATA_PREFIX)/%: %
 	@install -D -m 644 $< $@ || ( echo "NO THUMB $<" )