diff --git a/mozilla/webtools/bugzilla/.bzrrev b/mozilla/webtools/bugzilla/.bzrrev
index ee1dce059e9..4d04943378f 100644
--- a/mozilla/webtools/bugzilla/.bzrrev
+++ b/mozilla/webtools/bugzilla/.bzrrev
@@ -1 +1 @@
-9020
\ No newline at end of file
+9021
\ No newline at end of file
diff --git a/mozilla/webtools/bugzilla/.gitrev b/mozilla/webtools/bugzilla/.gitrev
index 0267ae15a37..8fb92d2692d 100644
--- a/mozilla/webtools/bugzilla/.gitrev
+++ b/mozilla/webtools/bugzilla/.gitrev
@@ -1 +1 @@
-0e18b44ee2dc59bf5b0816fd2a26a90b81057384
\ No newline at end of file
+b0df54c7f19387f72124b53431473374db26c0cf
\ No newline at end of file
diff --git a/mozilla/webtools/bugzilla/Bugzilla/Search.pm b/mozilla/webtools/bugzilla/Bugzilla/Search.pm
index 1c008bdfb5c..75a0fbdb45c 100644
--- a/mozilla/webtools/bugzilla/Bugzilla/Search.pm
+++ b/mozilla/webtools/bugzilla/Bugzilla/Search.pm
@@ -2053,6 +2053,13 @@ sub _quote_unless_numeric {
 
 sub build_subselect {
     my ($outer, $inner, $table, $cond, $negate) = @_;
+    if ($table =~ /\battach_data\b/) {
+        # It takes a long time to scan the whole attach_data table
+        # unconditionally, so we return the subselect and let the DB optimizer
+        # restrict the search based on other search criteria.
+        my $not = $negate ? "NOT" : "";
+        return "$outer $not IN (SELECT DISTINCT $inner FROM $table WHERE $cond)";
+    }
     # Execute subselects immediately to avoid dependent subqueries, which are
     # large performance hits on MySql
     my $q = "SELECT DISTINCT $inner FROM $table WHERE $cond";