diff --git a/src/backend/bs_repserver b/src/backend/bs_repserver
index 6eac2a1d74c..33f9ee375e0 100755
--- a/src/backend/bs_repserver
+++ b/src/backend/bs_repserver
@@ -69,6 +69,7 @@ use BSSched::ProjPacks;
 use BSRepServer;
 use BSRepServer::BuildInfo;
 use BSDispatcher::Constraints;
+use BSCando;
 use Build;
 
 use strict;
@@ -3584,6 +3585,17 @@ sub checkconstraints {
   my $prjconfconstraint = BSDispatcher::Constraints::list2struct($BSXML::constraints, \@list);
   $constraints = $constraints ? BSDispatcher::Constraints::mergeconstraints($prjconfconstraint, $constraints) : $prjconfconstraint;
 
+  my %harchcando;         # can the harch build an arch?
+  for my $harch (keys %BSCando::cando) {
+    for my $arch (@{$BSCando::cando{$harch}}) {
+      if ($arch =~ /^([^:]+):(.+)$/) {
+        $harchcando{"$harch/$1"} = $2;
+      } else {
+        $harchcando{"$harch/$arch"} = '';
+      }
+    }
+  }
+
   my $dispatch_constraints_info = {
     'project' => $projid ,
     'repoid' => $repoid,
@@ -3595,6 +3607,8 @@ sub checkconstraints {
   for my $workerstate (qw{idle building away dead down}) {
     my @workernames = sort(grep {!/^\./} BSUtil::ls("$workersdir/$workerstate"));
     for my $workername (@workernames) {
+      my ($harch) = split(':', $workername, 2);
+      next unless exists($harchcando{"$harch/$arch"});
       my $worker = readxml("$workersdir/$workerstate/$workername", $BSXML::worker, 1);
       next if $BSConfig::dispatch_constraint && !$BSConfig::dispatch_constraint->($dispatch_constraints_info, $worker, $constraints);
       next if $constraints && BSDispatcher::Constraints::oracle($worker, $constraints) <= 0;
diff --git a/src/backend/bs_srcserver b/src/backend/bs_srcserver
index 0e9151f8b64..136b8cca317 100755
--- a/src/backend/bs_srcserver
+++ b/src/backend/bs_srcserver
@@ -5695,15 +5695,14 @@ sub hello {
 ####################################################################
 
 sub getworkercap {
-  my ($cgi) = @_;
+  my ($cgi, $workerid) = @_;
   my $reposerver = $BSConfig::masterdispatcher || $BSConfig::reposerver; # no need to look for partitioning here
-  my @args = BSRPC::args($cgi, 'workerid');
   my $param = {
-    'uri' => "$reposerver/getworkercapabilities",
+    'uri' => "$reposerver/worker/$workerid",
     'timeout' => 60,
   };
 
-  my $worker_cap = BSWatcher::rpc($param, $BSXML::worker, @args);
+  my $worker_cap = BSWatcher::rpc($param, $BSXML::worker);
 
   return($worker_cap, $BSXML::worker);
 }