diff --git a/Python/marshal.c b/Python/marshal.c
index c2531197f8b..901b9c69742 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -654,7 +654,7 @@ r_object(RFILE *p)
 	}
 }
 
-PyObject *
+static PyObject *
 read_object(RFILE *p)
 {
 	PyObject *v;