diff --git a/test/merge_debian_isos b/test/merge_debian_isos
index 4ba33e63..00cbedd6 100755
--- a/test/merge_debian_isos
+++ b/test/merge_debian_isos
@@ -532,7 +532,7 @@ check_and_put_out_md5_grep() {
   fi
   if echo "$prev_path" | grep '^\.\/firmware\/' >/dev/null 2>&1
   then
-    if test "$was_multiple" = 1
+    if test "$was_multiple" = 1 && test "$multi_md5_differs" = 1
     then
       # There is the risk that the surviving file does not match prev_md5.
       # Better omit it.
@@ -573,12 +573,19 @@ polish_md5sum_txt() {
   prev_path=
   prev_md5=
   was_multiple=0
+  multi_md5_differs=0
 
   cat merged_md5sum.txt | \
   while read md5 path
   do
     if test "$path" = "$prev_path"
     then
+      if test "$md5" = "$prev_md5"
+      then
+        dummy=dummy
+      else
+        multi_md5_differs=1
+      fi
       was_multiple=1
   continue
     fi
@@ -590,6 +597,7 @@ polish_md5sum_txt() {
     prev_path="$path"
     prev_md5="$md5"
     was_multiple=0
+    multi_md5_differs=0
   done
 
   if test -n "$prev_path"
diff --git a/test/merge_debian_isos.sig b/test/merge_debian_isos.sig
index 733cc444..460c4905 100644
Binary files a/test/merge_debian_isos.sig and b/test/merge_debian_isos.sig differ