diff --git a/Makefile b/Makefile
index 53a872b..e1dfe6e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,8 @@
 cat: cat.o
 	ld -o cat cat.o
 
-cat.o: cat.s
-	nasm -f elf64 cat.s
+cat.o: cat.nasm
+	nasm -f elf64 cat.nasm
 
 .PHONY: clean
 clean:
diff --git a/cat.s b/cat.nasm
similarity index 100%
rename from cat.s
rename to cat.nasm