diff --git a/solenv/bin/modules/ExtensionsLst.pm b/solenv/bin/modules/ExtensionsLst.pm
index 60080ca..a56af40 100644
--- a/solenv/bin/modules/ExtensionsLst.pm
+++ b/solenv/bin/modules/ExtensionsLst.pm
@@ -423,6 +423,20 @@ sub Download (@)
         if ( ! -f $candidate)
         {
             push @missing, $entry;
+            print "downloading $candidate\n";
+        }
+        else
+        {
+            open(my $cur_oxt, $candidate) or next; # TODO die or next?
+            binmode($cur_oxt);
+            my $file_md5 = Digest::MD5->new->addfile(*$cur_oxt)->hexdigest;
+            close($cur_oxt);
+            if ($md5sum ne $file_md5)
+            {
+                push @missing, $entry;
+                print "updating $candidate\n";
+                unlink($candidate); # needed? rename overwrites, at least in Linux
+            }
         }
     }
     if ($#missing >= 0)