diff --git a/Topten.RichTextKit/Utils/Buffer.cs b/Topten.RichTextKit/Utils/Buffer.cs
index 9325096..e0b996f 100644
--- a/Topten.RichTextKit/Utils/Buffer.cs
+++ b/Topten.RichTextKit/Utils/Buffer.cs
@@ -110,7 +110,7 @@ bool GrowBuffer(int requiredLength)
                 newLength = requiredLength;
 
             // Allocate new buffer, only copying _length, not Data.Length
-            var newData = new T[requiredLength];
+            var newData = new T[newLength];
             Array.Copy(_data, 0, newData, 0, _length);
             _data = newData;