diff --git a/ext/json/parser/depend b/ext/json/parser/depend
index 498ffa964c..25e74781e6 100644
--- a/ext/json/parser/depend
+++ b/ext/json/parser/depend
@@ -1 +1 @@
-parser.o: parser.c parser.h $(srcdir)/../fbuffer/fbuffer.h
+parser.o: parser.c parser.h $(srcdir)/../fbuffer/fbuffer.h $(ruby_headers)