diff --git a/src/Humanizer/StringHumanizeExtensions.cs b/src/Humanizer/StringHumanizeExtensions.cs
index cf4f24ead..6142cbcba 100644
--- a/src/Humanizer/StringHumanizeExtensions.cs
+++ b/src/Humanizer/StringHumanizeExtensions.cs
@@ -32,8 +32,19 @@ public static partial class StringHumanizeExtensions
     private static Regex FreestandingSpacingCharRegex() => FreestandingSpacingCharRegexField;
 #endif
 
-    static string FromUnderscoreDashSeparatedWords(string input) =>
-        string.Join(" ", input.Split(['_', '-']));
+    static string FromUnderscoreDashSeparatedWords(string input)
+    {
+#if NET7_0_OR_GREATER
+        return string.Create(input.Length, input, (span, state) =>
+        {
+            state.AsSpan().CopyTo(span);
+            span.Replace('_', ' ');
+            span.Replace('-', ' ');
+        });
+#else
+        return input.Replace('_', ' ').Replace('-', ' ');
+#endif
+    }
 
     static string FromPascalCase(string input)
     {
@@ -160,4 +171,4 @@ internal static unsafe string Concat(char left, CharSpan right) =>
     internal static unsafe string Concat(CharSpan left, char right) =>
         Concat(left, new CharSpan(&right, 1));
 #endif
-}
\ No newline at end of file
+}