diff --git a/src/fix_enforce2d.h b/src/fix_enforce2d.h
index cdead78f6a..a3f79309dc 100644
--- a/src/fix_enforce2d.h
+++ b/src/fix_enforce2d.h
@@ -36,7 +36,7 @@ class FixEnforce2D : public Fix {
   void post_force_respa(int, int, int);
   void min_post_force(int);
 
- private:
+ protected:
   int nfixlist;
   class Fix **flist;
 };