diff --git a/mozilla/webtools/bugzilla/process_bug.cgi b/mozilla/webtools/bugzilla/process_bug.cgi
index fd0c3eb9d1d..18097d084b9 100755
--- a/mozilla/webtools/bugzilla/process_bug.cgi
+++ b/mozilla/webtools/bugzilla/process_bug.cgi
@@ -1110,6 +1110,17 @@ SWITCH: for ($cgi->param('knob')) {
 
             ChangeStatus('RESOLVED');
         }
+        else {
+            # You cannot use change_resolution if there is at least
+            # one open bug.
+            my $open_states = join(',', map {$dbh->quote($_)} BUG_STATE_OPEN);
+            my $idlist = join(',', @idlist);
+            my $is_open =
+              $dbh->selectrow_array("SELECT 1 FROM bugs WHERE bug_id IN ($idlist)
+                                     AND bug_status IN ($open_states)");
+
+            ThrowUserError('resolution_not_allowed') if $is_open;
+        }
 
         ChangeResolution($bug, $cgi->param('resolution'));
         last SWITCH;
diff --git a/mozilla/webtools/bugzilla/template/en/default/global/user-error.html.tmpl b/mozilla/webtools/bugzilla/template/en/default/global/user-error.html.tmpl
index b2a3624b28e..01368f06dc2 100644
--- a/mozilla/webtools/bugzilla/template/en/default/global/user-error.html.tmpl
+++ b/mozilla/webtools/bugzilla/template/en/default/global/user-error.html.tmpl
@@ -1286,6 +1286,10 @@
     [% title = "Summary Needed" %]
     You must enter a summary for this [% terms.bug %].
 
+  [% ELSIF error == "resolution_not_allowed" %]
+    [% title = "Resolution Not Allowed" %]
+    You cannot set a resolution for open [% terms.bugs %].
+
   [% ELSIF error == "saved_search_used_by_whines" %]
     [% title = "Saved Search In Use" %]
     [% docslinks = {'whining.html' => 'About Whining'} %]