diff --git a/MdeModulePkg/Universal/Disk/UdfDxe/File.c b/MdeModulePkg/Universal/Disk/UdfDxe/File.c
index 4aa0594f1a..45ce5e51f8 100644
--- a/MdeModulePkg/Universal/Disk/UdfDxe/File.c
+++ b/MdeModulePkg/Universal/Disk/UdfDxe/File.c
@@ -722,7 +722,7 @@ UdfSetPosition (
     // set to the EOF.
     //
     if (Position == 0xFFFFFFFFFFFFFFFF) {
-      PrivFileData->FilePosition = PrivFileData->FileSize - 1;
+      PrivFileData->FilePosition = PrivFileData->FileSize;
     } else {
       PrivFileData->FilePosition = Position;
     }