diff --git a/Python/compile.c b/Python/compile.c
index 5195f56..4649d32 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -3625,7 +3625,7 @@
 	a->a_postorder[a->a_nblocks++] = b;
 }
 
-int
+static int
 stackdepth_walk(struct compiler *c, basicblock *b, int depth, int maxdepth)
 {
 	int i;