ext/stack_frames/frame.c in stack_frames-0.1.2 vs ext/stack_frames/frame.c in stack_frames-0.1.3

@@ -17,10 +17,10 @@
 static size_t frame_memsize(const void *ptr)
 {
     return sizeof(frame_t);
 }
 
-const rb_data_type_t frame_data_type = {
+static const rb_data_type_t frame_data_type = {
     "stack_frames_frame",
     { frame_mark, RUBY_DEFAULT_FREE, frame_memsize, },
     NULL, NULL, RUBY_TYPED_FREE_IMMEDIATELY
 };