diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index 8bedab5c27a..c0240e2af02 100644
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -522,7 +522,7 @@ child_exec(char *const exec_array[],
         char *cur;
         _Py_write_noraise(errpipe_write, "OSError:", 8);
         cur = hex_errno + sizeof(hex_errno);
-        while (saved_errno != 0 && cur > hex_errno) {
+        while (saved_errno != 0 && cur != hex_errno) {
             *--cur = Py_hexdigits[saved_errno % 16];
             saved_errno /= 16;
         }