diff --git a/Jint.Tests/Runtime/Debugger/TestHelpers.cs b/Jint.Tests/Runtime/Debugger/TestHelpers.cs
index 3b0aa3138b..ea130ce18c 100644
--- a/Jint.Tests/Runtime/Debugger/TestHelpers.cs
+++ b/Jint.Tests/Runtime/Debugger/TestHelpers.cs
@@ -1,4 +1,5 @@
-using Esprima.Ast;
+using System.Globalization;
+using Esprima.Ast;
 using Jint.Runtime.Debugger;
 
 namespace Jint.Tests.Runtime.Debugger
@@ -68,5 +69,80 @@ public static void TestAtBreak(string script, Action<DebugInformation> breakHand
         {
             TestAtBreak(script, (engine, info) => breakHandler(info));
         }
+
+        public static void ShouldEqualWithDiff(this string actualValue, string expectedValue)
+        {
+            ShouldEqualWithDiff(actualValue, expectedValue, DiffStyle.Full, Console.Out);
+        }
+
+        public static void ShouldEqualWithDiff(this string actualValue, string expectedValue, DiffStyle diffStyle)
+        {
+            ShouldEqualWithDiff(actualValue, expectedValue, diffStyle, Console.Out);
+        }
+
+        public static void ShouldEqualWithDiff(this string actualValue, string expectedValue, DiffStyle diffStyle, TextWriter output)
+        {
+            if (actualValue == null || expectedValue == null)
+            {
+                //Assert.AreEqual(expectedValue, actualValue);
+                Assert.Equal(expectedValue, actualValue);
+                return;
+            }
+
+            //if (actualValue.Equals(expectedValue, StringComparison.Ordinal)) return;
+
+            output.WriteLine("  Idx Expected  Actual");
+            output.WriteLine("-------------------------");
+            int maxLen = Math.Max(actualValue.Length, expectedValue.Length);
+            int minLen = Math.Min(actualValue.Length, expectedValue.Length);
+            for (int i = 0; i < maxLen; i++)
+            {
+                if (diffStyle != DiffStyle.Minimal || i >= minLen || actualValue[i] != expectedValue[i])
+                {
+                    output.WriteLine("{0} {1,-3} {2,-4} {3,-3}  {4,-4} {5,-3}",
+                        i < minLen && actualValue[i] == expectedValue[i] ? " " : "*", // put a mark beside a differing row
+                        i, // the index
+                        i < expectedValue.Length ? ((int) expectedValue[i]).ToString() : "", // character decimal value
+                        i < expectedValue.Length ? expectedValue[i].ToSafeString() : "", // character safe string
+                        i < actualValue.Length ? ((int) actualValue[i]).ToString() : "", // character decimal value
+                        i < actualValue.Length ? actualValue[i].ToSafeString() : "" // character safe string
+                    );
+                }
+            }
+            output.WriteLine();
+
+            //Assert.AreEqual(expectedValue, actualValue);
+            Assert.Equal(expectedValue, actualValue);
+        }
+
+        private static string ToSafeString(this char c)
+        {
+            if (Char.IsControl(c) || Char.IsWhiteSpace(c))
+            {
+                switch (c)
+                {
+                    case '\r':
+                        return @"\r";
+                    case '\n':
+                        return @"\n";
+                    case '\t':
+                        return @"\t";
+                    case '\a':
+                        return @"\a";
+                    case '\v':
+                        return @"\v";
+                    case '\f':
+                        return @"\f";
+                    default:
+                        return String.Format("\\u{0:X};", (int) c);
+                }
+            }
+            return c.ToString(CultureInfo.InvariantCulture);
+        }
+    }
+    public enum DiffStyle
+    {
+        Full,
+        Minimal
     }
 }
diff --git a/Jint.Tests/Runtime/NumberTests.cs b/Jint.Tests/Runtime/NumberTests.cs
index 43aefc1ef7..de5177f5d5 100644
--- a/Jint.Tests/Runtime/NumberTests.cs
+++ b/Jint.Tests/Runtime/NumberTests.cs
@@ -1,4 +1,6 @@
+using System.Globalization;
 using Jint.Runtime;
+using Jint.Tests.Runtime.Debugger;
 
 namespace Jint.Tests.Runtime
 {
@@ -129,8 +131,7 @@ public void ParseFloat(string input, double result)
         public void ToLocaleString(string parseNumber, string culture, string result)
         {
             var value = _engine.Evaluate($"({parseNumber}).toLocaleString('{culture}')").AsString();
-            // Normalized strings to handle different space characters.
-            Assert.Equal(result.Normalize(), value.Normalize());
+            TestHelpers.ShouldEqualWithDiff(result, value);
         }
 
         [Theory]