diff --git a/docs/spelling.txt b/docs/spelling.txt
index 3f36d12d8..b9961c69c 100644
--- a/docs/spelling.txt
+++ b/docs/spelling.txt
@@ -1108,6 +1108,7 @@ unbased
 uncomment
 undef
 undefineall
+undefs
 undriven
 ungetc
 unhandled