diff --git a/pkg/database/migrate/mysql.go b/pkg/database/migrate/mysql.go
index 248b510c4..7fe29ce65 100644
--- a/pkg/database/migrate/mysql.go
+++ b/pkg/database/migrate/mysql.go
@@ -21,7 +21,8 @@ func MySQL(tx *sql.Tx) *MigrationDriver {
 }
 
 func (m *mysqlDriver) CreateTable(tableName string, args []string) (sql.Result, error) {
-	return m.Tx.Exec(fmt.Sprintf("CREATE TABLE %s (%s) ROW_FORMAT=DYNAMIC", tableName, strings.Join(args, ", ")))
+	return m.Tx.Exec(fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s (%s) ROW_FORMAT=DYNAMIC",
+		tableName, strings.Join(args, ", ")))
 }
 
 func (m *mysqlDriver) RenameTable(tableName, newName string) (sql.Result, error) {
@@ -41,6 +42,9 @@ func (m *mysqlDriver) ChangeColumn(tableName, columnName, newSpecs string) (sql.
 }
 
 func (m *mysqlDriver) DropColumns(tableName string, columnsToDrop ...string) (sql.Result, error) {
+	if len(columnsToDrop) == 0 {
+		return nil, fmt.Errorf("No columns to drop.")
+	}
 	for k, v := range columnsToDrop {
 		columnsToDrop[k] = fmt.Sprintf("DROP %s", v)
 	}
diff --git a/pkg/queue/build_runner.go b/pkg/queue/build_runner.go
index 0c04ad102..ca9606f08 100644
--- a/pkg/queue/build_runner.go
+++ b/pkg/queue/build_runner.go
@@ -11,7 +11,7 @@ import (
 )
 
 type BuildRunner interface {
-	Run(buildScript *script.Build, repo *repo.Repo, key []byte, buildOutput io.Writer) (success bool, err error)
+	Run(buildScript *script.Build, repo *repo.Repo, key []byte, privileged bool, buildOutput io.Writer) (success bool, err error)
 }
 
 type buildRunner struct {
@@ -26,11 +26,12 @@ func NewBuildRunner(dockerClient *docker.Client, timeout time.Duration) BuildRun
 	}
 }
 
-func (runner *buildRunner) Run(buildScript *script.Build, repo *repo.Repo, key []byte, buildOutput io.Writer) (bool, error) {
+func (runner *buildRunner) Run(buildScript *script.Build, repo *repo.Repo, key []byte, privileged bool, buildOutput io.Writer) (bool, error) {
 	builder := build.New(runner.dockerClient)
 	builder.Build = buildScript
 	builder.Repo = repo
 	builder.Key = key
+	builder.Privileged = privileged
 	builder.Stdout = buildOutput
 	builder.Timeout = runner.timeout
 
diff --git a/pkg/queue/worker.go b/pkg/queue/worker.go
index 174eb69eb..26612aade 100644
--- a/pkg/queue/worker.go
+++ b/pkg/queue/worker.go
@@ -183,6 +183,7 @@ func (w *worker) runBuild(task *BuildTask, buf io.Writer) (bool, error) {
 		task.Script,
 		repo,
 		[]byte(task.Repo.PrivateKey),
+		task.Repo.Privileged,
 		buf,
 	)
 }