diff --git a/src/log4net/Appender/RollingFileAppender.cs b/src/log4net/Appender/RollingFileAppender.cs
index a91b7e27..68578975 100644
--- a/src/log4net/Appender/RollingFileAppender.cs
+++ b/src/log4net/Appender/RollingFileAppender.cs
@@ -1112,7 +1112,7 @@ protected void RollOverTime(bool fileIsOpen)
   /// also checks for existence of target file and deletes if it does.
   /// </para>
   /// </remarks>
-  protected void RollFile(string fromFile, string toFile)
+  protected virtual void RollFile(string fromFile, string toFile)
   {
     if (FileExists(fromFile))
     {