diff --git a/libc/tools/gensyscalls.py b/libc/tools/gensyscalls.py
index 558b004..4f33777 100755
--- a/libc/tools/gensyscalls.py
+++ b/libc/tools/gensyscalls.py
@@ -88,7 +88,7 @@
     ecall
 
     li      a7, -MAX_ERRNO
-    bgtu    a0, a7, 1f
+    bgeu    a0, a7, 1f
 
     ret
 1: