diff --git a/ext/ripper/depend b/ext/ripper/depend
index e8582f5c6607ca..531672d285f6dc 100644
--- a/ext/ripper/depend
+++ b/ext/ripper/depend
@@ -12,7 +12,7 @@ ripper.o: ripper.c
 
 .y.c:
 	$(ECHO) compiling compiler $<
-	$(Q) $(BISON) -t -v -o$@ -h$*.h - parse.y < $<
+	$(Q) $(BISON) -t -v -o$@ -h$*.h - $< < $<
 
 all: check
 static: check