1 files changed, 1 insertions, 0 deletions
diff --git a/struct.c b/struct.c
index 5572a92135..136ba0acee 100644
--- a/struct.c
+++ b/struct.c
@@ -10,6 +10,7 @@
 **********************************************************************/
 
 #include "ruby/ruby.h"
+#include "internal.h"
 
 VALUE rb_cStruct;
 static ID id_members;