diff --git a/DokanNet/DokanOperationProxy.cs b/DokanNet/DokanOperationProxy.cs
index 2558662e..4929e992 100644
--- a/DokanNet/DokanOperationProxy.cs
+++ b/DokanNet/DokanOperationProxy.cs
@@ -408,7 +408,7 @@ public NtStatus ReadFileProxy(
                     try
                     {
                         result = operations.ReadFile(rawFileName, buffer, out rawReadLength, rawOffset, rawFileInfo);
-                        Marshal.Copy(buffer, 0, rawBuffer, (int)rawBufferLength);
+                        Marshal.Copy(buffer, 0, rawBuffer, rawReadLength);
                     }
                     finally
                     {