diff --git a/src/Humanizer.Tests/TruncatorTests.cs b/src/Humanizer.Tests/TruncatorTests.cs
index 7a8fcabfa..b9dfc57d1 100644
--- a/src/Humanizer.Tests/TruncatorTests.cs
+++ b/src/Humanizer.Tests/TruncatorTests.cs
@@ -10,6 +10,15 @@
     public void Truncate(string? input, int length, string? expectedOutput) =>
         Assert.Equal(expectedOutput, input.Truncate(length));
 
+    [Theory]
+    [InlineData("short text", 20, null, "short text")]
+    [InlineData("short text", 20, "trunc", "short text")]
+    [InlineData("short text", 20, "very long truncation string", "short text")]
+    [InlineData("Text longer than truncate length", 10, "very long truncation string", "Text longe")]
+    [InlineData("Text longer than truncate length", 10, "trunc", "Text trunc")]
+    public void TruncateWithCustomTruncationString(string? input, int length, string? trunactionString, string? expectedOutput) =>
+        Assert.Equal(expectedOutput, input.Truncate(length, trunactionString));
+
     [Theory]
     [InlineData(null, 10, null)]
     [InlineData("", 10, "")]
diff --git a/src/Humanizer/Truncation/FixedLengthTruncator.cs b/src/Humanizer/Truncation/FixedLengthTruncator.cs
index 42af71d29..f39a56f9b 100644
--- a/src/Humanizer/Truncation/FixedLengthTruncator.cs
+++ b/src/Humanizer/Truncation/FixedLengthTruncator.cs
@@ -13,7 +13,7 @@ class FixedLengthTruncator : ITruncator
             return null;
         }
 
-        if (value.Length == 0)
+        if (value.Length == 0 || value.Length <= length)
         {
             return value;
         }
@@ -25,15 +25,6 @@ class FixedLengthTruncator : ITruncator
                 : value.Substring(value.Length - length);
         }
 
-        if (truncateFrom == TruncateFrom.Left)
-        {
-            return value.Length > length
-                ? StringHumanizeExtensions.Concat(truncationString.AsSpan(), value.AsSpan(value.Length - length + truncationString.Length))
-                : value;
-        }
-
-        return value.Length > length
-            ? StringHumanizeExtensions.Concat(value.AsSpan(0, length - truncationString.Length), truncationString.AsSpan())
-            : value;
+        return truncateFrom == TruncateFrom.Left ? StringHumanizeExtensions.Concat(truncationString.AsSpan(), value.AsSpan(value.Length - length + truncationString.Length)) : StringHumanizeExtensions.Concat(value.AsSpan(0, length - truncationString.Length), truncationString.AsSpan());
     }
 }
\ No newline at end of file