diff --git a/src/filo-fs-ext2.adb b/src/filo-fs-ext2.adb
index 8197733..7b138b2 100644
--- a/src/filo-fs-ext2.adb
+++ b/src/filo-fs-ext2.adb
@@ -356,6 +356,7 @@
 
       Extent_Header_Size : constant := 12;
       Extent_Header_Magic : constant := 16#f30a#;
+      Initialized_Extent_Max_Len : constant := 2 ** 15;
       subtype Extent_Off is Natural range 0 .. Extent_Header_Size;
       subtype Extent_Idx is Natural range 1 .. (Max_Block_Index'Last + 1) / Extent_Header_Size - 1;
       Dynamic_Max_Index : constant Extent_Idx := State.Static.Block_Size / Extent_Header_Size - 1;
@@ -561,7 +562,7 @@
       end if;
 
       Success :=
-         Length > 0 and then
+         (0 < Length and Length <= Initialized_Extent_Max_Len) and then
          Logical_Off <= FSBlock_Logical'Last - Length and then
          Logical < Logical_Off + Length and then
          FSBlock_Offset (Logical - Logical_Off) <= FSBlock_Offset'Last - Physical;