diff --git a/master.cfg b/master.cfg
index 33a4b7c..b7d768a 100644
--- a/master.cfg
+++ b/master.cfg
@@ -598,6 +598,20 @@ all_gdb_filter = ChangeFilter (branch_fn = should_watch_branch)
 def DefaultGDBCanStartBuild (builder, buildslave, buildrequest):
     return not builder.building
 
+tests_accepted_re = re.compile ("(gdb/|bfd/|binutils/).*")
+
+def DefaultGDBfileIsImportant (change):
+    """Implementation of fileIsImportant method, in order to decide which
+changes to build on GDB."""
+    if 'GDB Administrator' in change.who:
+        return False
+
+    for filename in change.files:
+        if re.match (tests_accepted_re, filename):
+            return True
+
+    return False
+
 ###############################
 #### Configuration loading ####
 ###############################
@@ -613,6 +627,7 @@ def load_config (c):
     passwd = load (open ("lib/passwords.json"))
 
     random.seed ()
+
     c['slaves'] = [BuildSlave (slave['name'], passwd[slave['name']],
                                max_builds = 1,
                                properties = { 'jobs' : slave['jobs'],
@@ -624,6 +639,7 @@ def load_config (c):
         if "change_filter" in s:
             s['change_filter'] = globals ()[s['change_filter']]
         s['treeStableTimer'] = None
+        s['fileIsImportant'] = DefaultGDBfileIsImportant
         kls = globals ()[s.pop ('type')]
         s = dict (map (lambda key_value_pair : (str (key_value_pair[0]),
                                                 key_value_pair[1]),