diff --git a/src/Hydra/programs/Runner.pl b/src/Hydra/programs/Runner.pl
index f7d8d56c..e804a80f 100644
--- a/src/Hydra/programs/Runner.pl
+++ b/src/Hydra/programs/Runner.pl
@@ -27,11 +27,16 @@ $db->txn_do(sub {
 });
 
 
+sub logfileForBuild {
+    my ($id) = @_;
+    return getcwd . "/logs/" . $id;
+}
+
+
 sub checkJobs {
     print "looking for runnable jobs...\n";
 
     my @jobsStarted;
-    my $logfile;
 
     $db->txn_do(sub {
 
@@ -67,8 +72,7 @@ sub checkJobs {
                 "starting ", scalar(@jobs), " builds\n";
 
             foreach my $job (@jobs) {
-                $logfile = getcwd . "/logs/" . $job->id;
-                unlink $logfile;
+                unlink(logfileForBuild $job->id);
                 $job->schedulingInfo->busy(1);
                 $job->schedulingInfo->locker($$);
                 $job->schedulingInfo->logfile($logfile);
@@ -89,6 +93,7 @@ sub checkJobs {
             my $child = fork();
             die unless defined $child;
             if ($child == 0) {
+                my $logfile = logfileForBuild $job->id;
                 open LOG, ">$logfile" or die;
                 POSIX::dup2(fileno(LOG), 1) or die;
                 POSIX::dup2(fileno(LOG), 2) or die;