diff --git a/src/hb-open-type.hh b/src/hb-open-type.hh
index 642332cb9..6b3a4612a 100644
--- a/src/hb-open-type.hh
+++ b/src/hb-open-type.hh
@@ -209,7 +209,7 @@ struct HBUINT32VAR
   }
 
   protected:
-  unsigned char v[1];
+  unsigned char v[5];
 
   public:
   DEFINE_SIZE_MIN (1);
diff --git a/src/hb.hh b/src/hb.hh
index 0ceeb99f5..fe466fe1f 100644
--- a/src/hb.hh
+++ b/src/hb.hh
@@ -84,6 +84,7 @@
 #pragma GCC diagnostic error   "-Wredundant-decls"
 #pragma GCC diagnostic error   "-Wreorder"
 #pragma GCC diagnostic error   "-Wsign-compare"
+#pragma GCC diagnostic error   "-Wstrict-flex-arrays"
 #pragma GCC diagnostic error   "-Wstrict-prototypes"
 #pragma GCC diagnostic error   "-Wstring-conversion"
 #pragma GCC diagnostic error   "-Wswitch-enum"