diff --git a/xtask/src/version.rs b/xtask/src/version.rs
index 795070577..50fb8f040 100644
--- a/xtask/src/version.rs
+++ b/xtask/src/version.rs
@@ -147,7 +147,7 @@ mod tests {
         for ok in ["0.1.0", "1.20.300", "1.0.0-rc.1", "1.0.0-alpha", "1.0.0-x-y.2"] {
             assert!(validate(ok).is_ok(), "{ok}");
         }
-        for bad in ["1.0", "1.0.0.0", "v1.0.0", "01.0.0", "1.0.0-", "1.0.0-a..b", "1.0.0+meta", "1.a.0", ""] {
+        for bad in ["1.0", "1.0.0.0", "v1.0.0", "01.0.0", "1.0.0-", "1.0.0-a..b", "1.0.0+meta", "1.a.0", "18446744073709551616.0.0", ""] {
             assert!(validate(bad).is_err(), "{bad}");
         }
         assert!(replace(MANIFEST, "nope").is_err());