diff --git a/src/filo-fs-iso9660.adb b/src/filo-fs-iso9660.adb
index e4bc3df..f232c86 100644
--- a/src/filo-fs-iso9660.adb
+++ b/src/filo-fs-iso9660.adb
@@ -166,9 +166,16 @@
       is
       begin
          for I in Str'Range loop
-            if Character'Pos (Str (I)) /= Buf (Buf'First + (I - Str'First)) then
-               return False;
-            end if;
+            declare
+               Chr : constant Unsigned_8 :=
+                  (if 'a' <= Str (I) and Str (I) <= 'z' then
+                     Character'Pos (Str (I)) - Character'Pos ('a') + Character'Pos ('A')
+                   else Character'Pos (Str (I)));
+            begin
+               if Chr /= Buf (Buf'First + (I - Str'First)) then
+                  return False;
+               end if;
+            end;
          end loop;
          return True;
       end Str_Buf_Equal;