diff --git a/Makefile b/Makefile
index da722f9..bb2ed0c 100644
--- a/Makefile
+++ b/Makefile
@@ -17,17 +17,17 @@ export TEXTURES := $(wildcard $(TEXTURESET_FOLDER)/*)
 
 ### RECIPE PART ###
 
-all : previews del_obsolete export
+all : del_obsolete export
 
-previews: $(SBSARFILES)
+previews: $(SBSARFILES) | subformats
 	$(MAKE) -f Makefile_previews all
 
 subformats: $(SBSARFILES)
 	$(MAKE) -f Makefile_subformats all
 
-del_obsolete: $(SBS_DIR)
-	@ for material in $(TEXTURES); do \
-	rootname=$$(echo $$material | sed -r 's|$(TEXTURESET_FOLDER)/(.*)_.*|\1|');\
+del_obsolete: $(SBS_DIR) | previews
+	@ for material in $$(ls $(SBSAR_DIR)); do \
+	rootname=$$(echo $$material | sed -r 's|(.*)\.sbsar|\1|');\
 	sbs_name=$(SBS_DIR)/$$rootname.sbs ;\
 	if [ ! -f $$sbs_name ] ;\
 	then echo "CLEANUP : The corresponding $$sbs_name doesn’t exist any more, deleting the corresponding obsolete files :" ;\