diff --git a/lib/rb/ext/struct.c b/lib/rb/ext/struct.c
index d719e33..5a9a679 100644
--- a/lib/rb/ext/struct.c
+++ b/lib/rb/ext/struct.c
@@ -20,6 +20,7 @@
 #include "struct.h"
 #include "constants.h"
 #include "macros.h"
+#include "strlcpy.h"
 
 VALUE thrift_union_class;