Fix an incorrect return type.
diff --git a/Modules/_struct.c b/Modules/_struct.c
index e05fb73..5113b93 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -1145,7 +1145,7 @@
 
 /* Align a size according to a format code */
 
-static int
+static Py_ssize_t
 align(Py_ssize_t size, char c, const formatdef *e)
 {
     if (e->format == c) {