1 files changed, 1 insertions, 0 deletions
diff --git a/gc.h b/gc.h
index 094b941061..96d22a6e09 100644
--- a/gc.h
+++ b/gc.h
@@ -81,6 +81,7 @@ int ruby_get_stack_grow_direction(volatile VALUE *addr);
 #define STACK_GROW_DIR_DETECTION VALUE stack_grow_dir_detection
 #define STACK_DIR_UPPER(a,b) STACK_UPPER(&stack_grow_dir_detection, (a), (b))
 #endif
+#define IS_STACK_DIR_UPPER() STACK_DIR_UPPER(1,0)
 
 #if defined __GNUC__ && __GNUC__ >= 4
 #pragma GCC visibility push(default)