diff --git a/NPLib/Makefile b/NPLib/Makefile
index 6222f84cf8460e955606c9dd14cec5d317b8a2cd..4a530248935088509bbfa973ba9d6ace8fded96b 100644
--- a/NPLib/Makefile
+++ b/NPLib/Makefile
@@ -52,4 +52,4 @@ distclean:
 	rm -f ./*/*Dict*
 	rm -f ./*/*.o
 	@echo " + Deleting shared libraries files in detector directory"
-	rm -f ./*/*.s
+	rm -f ./*/*.so