diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 4469e3c..64f5754 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -475,7 +475,7 @@
         if (new_stack.depth > current_stack.depth ||
             top_block(&new_stack)->start_line != current_block_at_new_depth->start_line) {
             unsigned char target_kind = top_block(&new_stack)->kind;
-            char *msg;
+            const char *msg;
             if (target_kind == POP_EXCEPT) {
                 msg = "can't jump into an 'except' block as there's no exception";
             }