diff --git a/projects/Makefile b/projects/Makefile
index dbdf636..d582c40 100644
--- a/projects/Makefile
+++ b/projects/Makefile
@@ -1,6 +1,8 @@
 all:
 	for d in `ls -d project_*/`; do \
 		echo "Processing $$d" ; \
+		a=$$(echo $$d*.tex) ; \
+		rm $${a%.tex}.zip ; \
 		cd $$d; $(MAKE) zip ; cd .. ; \
 	done
 
diff --git a/projects/project_input_resistance/resistance.zip b/projects/project_input_resistance/resistance.zip
deleted file mode 100644
index 7d37fc6..0000000
Binary files a/projects/project_input_resistance/resistance.zip and /dev/null differ