diff --git a/src/System.Management.Automation/utils/StringUtil.cs b/src/System.Management.Automation/utils/StringUtil.cs
index 8daf31866df..98cf1081711 100644
--- a/src/System.Management.Automation/utils/StringUtil.cs
+++ b/src/System.Management.Automation/utils/StringUtil.cs
@@ -243,11 +243,7 @@ internal static string VtSubstring(this string str, int startOffset, int length,
             }
             else
             {
-                int capacity = length + prependStr?.Length ?? 0 + appendStr?.Length ?? 0;
-                return new StringBuilder(prependStr, capacity)
-                    .Append(str, startOffset, length)
-                    .Append(appendStr)
-                    .ToString();
+                return string.Concat(prependStr, str.AsSpan(startOffset, length), appendStr);
             }
         }