diff --git a/common.mk.in b/common.mk.in
index 12d4770..53cacf1 100644
--- a/common.mk.in
+++ b/common.mk.in
@@ -55,6 +55,8 @@ $(OUTDIR)%.js: %.js
 	cp -f $< $@
 $(OUTDIR)%.txt: %.txt
 	cp -f $< $@
+$(OUTDIR)%.pdf: %.pdf
+	cp -f $< $@
 $(OUTDIR)%.der: %.der
 	cp -f $< $@
 $(OUTDIR)%.pem: %.pem