diff --git a/make-includes/standard_rules.make b/make-includes/standard_rules.make
index 7875a5c..edf6f85 100755
--- a/make-includes/standard_rules.make
+++ b/make-includes/standard_rules.make
@@ -108,6 +108,7 @@
 %-BG-blur.png: %.tif
 	$(CONVERT) -blur 0.5 $< $(IMGDIR)/$*.png
 	$(CONVERT) $(IMGDIR)/$*.png -threshold "-1" -depth 16 - | $(COMPOSITE) -dissolve 33% $(IMGDIR)/$*.png - $(IMGDIR)/$@
+	@rm -f $(IMGDIR)/$*.png
 #
 # PNG from PICT.
 #