diff --git a/src/filo-fs-ext2.adb b/src/filo-fs-ext2.adb
index 903820b..0385cf4 100644
--- a/src/filo-fs-ext2.adb
+++ b/src/filo-fs-ext2.adb
@@ -426,7 +426,7 @@
       function Bin_Search (Buf : Buffer_Type; Refs : Extent_Idx) return Extent_Idx
       with
          Pre =>
-            Buf'Length in 2 * Extent_Header_Size .. Max_Block_Index'Last and then
+            Buf'Length in 2 * Extent_Header_Size .. Block_Size'Last and then
             Refs in 1 .. Extent_Idx (Buf'Length / Extent_Header_Size - 1) and then
             Extent_Logical (Buf, 1) <= Logical,
          Post =>
@@ -785,7 +785,7 @@
       File_Len := 0;
       File_Type := FS.File_Type'First;
 
-      if File_Name'Length > File_Name_Max then
+      if File_Name'Length not in 1 .. File_Name_Max then
          Success := False;
          return;
       end if;