# must fail: response_plus_first
# a Content-Range number may carry a sign (session::digits)
diff --git a/wai/wai-rs/src/http_binding/session.rs b/wai/wai-rs/src/http_binding/session.rs
index 4730c192..8b8f7e67 100644
--- a/wai/wai-rs/src/http_binding/session.rs
+++ b/wai/wai-rs/src/http_binding/session.rs
@@ -194,7 +194,7 @@ impl Selector {
 /// Whether `s` is one or more ASCII digits: the `1*DIGIT` of RFC 9110 §14.4. No sign,
 /// separator, space or other script's digit.
 fn digits(s: &str) -> Option<u64> {
-    if s.is_empty() || !s.bytes().all(|b| b.is_ascii_digit()) {
+    if s.is_empty() {
         return None;
     }
     s.parse().ok()