diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 8dc079e..e8de3e6 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -3439,11 +3439,11 @@
 #endif
 
 #ifdef HAVE_SPAWNV
-        if (ins(d, "_P_WAIT", (long)_P_WAIT)) return -1;
-        if (ins(d, "_P_NOWAIT", (long)_P_NOWAIT)) return -1;
-        if (ins(d, "_P_OVERLAY", (long)_OLD_P_OVERLAY)) return -1;
-        if (ins(d, "_P_NOWAITO", (long)_P_NOWAITO)) return -1;
-        if (ins(d, "_P_DETACH", (long)_P_DETACH)) return -1;
+        if (ins(d, "P_WAIT", (long)_P_WAIT)) return -1;
+        if (ins(d, "P_NOWAIT", (long)_P_NOWAIT)) return -1;
+        if (ins(d, "P_OVERLAY", (long)_OLD_P_OVERLAY)) return -1;
+        if (ins(d, "P_NOWAITO", (long)_P_NOWAITO)) return -1;
+        if (ins(d, "P_DETACH", (long)_P_DETACH)) return -1;
 #endif
 
 #if defined(PYOS_OS2)