diff --git a/make-includes/build_misc_rules.make b/make-includes/build_misc_rules.make
index d0be5a3..f4b4215 100755
--- a/make-includes/build_misc_rules.make
+++ b/make-includes/build_misc_rules.make
@@ -60,7 +60,7 @@
 # PDF files exist. They will be caught by by the "clean" target though.
 #
 TIDY_FILES+=*.tmp *.out *.log *.nav *.toc *.snm *.head *.dvi \
-	*-derived.xml
+	*-derived.xml $(IMGDIR)/*-tmp.pdf
 CLEAN_FILES+=*.aux *.pdf *.html