diff --git a/ext/ripper/ripper_init.c.tmpl b/ext/ripper/ripper_init.c.tmpl
index 98f260f8b1ab6d..40c583eeaebcb4 100644
--- a/ext/ripper/ripper_init.c.tmpl
+++ b/ext/ripper/ripper_init.c.tmpl
@@ -1,6 +1,7 @@
 #include "ruby/ruby.h"
 #include "ruby/encoding.h"
 #include "internal.h"
+#include "internal/imemo.h" /* needed by ruby_parser.h */
 #include "internal/parse.h"
 #include "internal/ruby_parser.h"
 #include "node.h"