2 files changed, 6 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index e1c3032dc8..424a88e214 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Oct  9 11:37:19 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* vm_core.h (VM_ASSERT): stringify expr here before expansion in
+	  RUBY_ASSERT_WHEN.
+
 Sat Oct  8 10:54:22 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/-test-/memory_status/memory_status.c (read_status): use
diff --git a/vm_core.h b/vm_core.h
index ccba902a36..f3e9a72cb0 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -46,7 +46,7 @@
 
 #if VM_CHECK_MODE > 0
 #define VM_ASSERT(expr) ( \
-	RUBY_ASSERT_WHEN(VM_CHECK_MODE > 0, expr))
+	RUBY_ASSERT_MESG_WHEN(VM_CHECK_MODE > 0, expr, #expr))
 
 #define VM_UNREACHABLE(func) rb_bug(#func ": unreachable")