diff --git a/Makefile b/Makefile
index b3ffbe2..4273b6f 100644
--- a/Makefile
+++ b/Makefile
@@ -254,7 +254,7 @@ TAGS:
 
 cscope:
 	rm -f ./cscope.*
-	find . -name "*.[ch]" -print | sed 's,^\./,,' > ./cscope.files
+	find $$PWD -name "*.[chsS]" -print | sed 's,^\./,,' > ./cscope.files
 	cscope -b
 
 # documentation