diff --git a/src/tools/tidy/src/style.rs b/src/tools/tidy/src/style.rs
index f2902bbc634c..fb5cde4b1117 100644
--- a/src/tools/tidy/src/style.rs
+++ b/src/tools/tidy/src/style.rs
@@ -107,14 +107,13 @@ const ROOT_PROBLEMATIC_CONSTS: &[u32] = &[
     173390526,
 ];
 
-fn generate_problematic_regex(
+fn generate_problematic_strings(
     consts: &[u32],
     letter_digit: &FxHashMap<char, char>,
-) -> RegexSet {
-    RegexSet::new(
-        generate_problems(consts, letter_digit)
-            .flat_map(|v| vec![v.to_string(), format!("{:x}", v), format!("{:X}", v)])
-    ).unwrap()
+) -> Vec<String> {
+    generate_problems(consts, letter_digit)
+        .flat_map(|v| vec![v.to_string(), format!("{:x}", v), format!("{:X}", v)])
+	    .collect()
 }
 
 const INTERNAL_COMPILER_DOCS_LINE: &str = "#### This error code is internal to the compiler and will not be emitted with normal Rust code.";
@@ -313,10 +312,11 @@ pub fn check(path: &Path, bad: &mut bool) {
         // We only check CSS files in rustdoc.
         path.extension().map_or(false, |e| e == "css") && !is_in(path, "src", "librustdoc")
     }
-    let problematic_regex = generate_problematic_regex(
+    let problematic_consts_strings = generate_problematic_strings(
         ROOT_PROBLEMATIC_CONSTS,
         &[('A', '4'), ('B', '8'), ('E', '3')].iter().cloned().collect(),
     );
+	let problematic_regex = RegexSet::new(problematic_consts_strings.as_slice()).unwrap();
 
     walk(path, skip, &mut |entry, contents| {
         let file = entry.path();