1 files changed, 3 insertions, 3 deletions
diff --git a/vm_core.h b/vm_core.h
index ff54c2928d..a42c8b7170 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -738,9 +738,9 @@ typedef struct {
 
     VALUE envval;		/* for GC mark */
     VALUE blockprocval;
-    int safe_level;
-    int is_from_method;
-    int is_lambda;
+    int8_t safe_level;		/* 0..4 */
+    int8_t is_from_method;	/* bool */
+    int8_t is_lambda;		/* bool */
 } rb_proc_t;
 
 #define GetEnvPtr(obj, ptr) \