diff --git a/src/patch/mod.rs b/src/patch/mod.rs
index 738521b9..af99160c 100644
--- a/src/patch/mod.rs
+++ b/src/patch/mod.rs
@@ -1,6 +1,7 @@
 pub mod patch_cli;
 
 use globset::Glob;
+use regex::Regex;
 use std::fs::File;
 use std::io::{Read, Write};
 use std::path::{Path, PathBuf};
@@ -571,19 +572,15 @@ fn make_cpu(cmod: &Hash) -> Result<CpuBuilder> {
 /// Find left and right indices of enumeration token in specification string
 fn spec_ind(spec: &str) -> (usize, usize) {
     let spec = spec.split(',').next().unwrap_or(spec);
-    let li = spec
-        .bytes()
-        .position(|b| b == b'*')
-        .or_else(|| spec.bytes().position(|b| b == b'?'))
-        .or_else(|| spec.bytes().position(|b| b == b'['))
-        .unwrap();
-    let ri = spec
-        .bytes()
-        .rev()
-        .position(|b| b == b'*')
-        .or_else(|| spec.bytes().rev().position(|b| b == b'?'))
-        .or_else(|| spec.bytes().rev().position(|b| b == b']'))
-        .unwrap();
+    let re = Regex::new(
+        r"^\w*((?:[\?*]|\[\d+(?:-\d+)?\]|\[[a-zA-Z]+(?:-[a-zA-Z]+)?\])+)\w*$",
+    )
+    .unwrap();
+    let caps = re.captures(spec).unwrap();
+    let spec = caps.get(0).unwrap();
+    let token = caps.get(1).unwrap();
+    let li = token.start();
+    let ri = spec.end() - token.end();
     (li, ri)
 }