diff --git a/server/main.go b/server/main.go
index 65c2202a..91a2cbe4 100644
--- a/server/main.go
+++ b/server/main.go
@@ -93,6 +93,9 @@ func main() {
 	perms := perm.NewManager(db)
 	commits := commit.NewManager(db)
 
+	// cancel all previously running builds
+	go commits.CancelAll()
+
 	// setup the session managers
 	sess := session.NewSession(users)
 
diff --git a/server/resource/commit/manager.go b/server/resource/commit/manager.go
index 21c0e9d2..96bf8766 100644
--- a/server/resource/commit/manager.go
+++ b/server/resource/commit/manager.go
@@ -43,6 +43,10 @@ type CommitManager interface {
 
 	// Delete removes the commit from the datastore.
 	Delete(commit *Commit) error
+
+	// CancelAll will update the status of all Started or Pending
+	// builds to a status of Killed (cancelled).
+	CancelAll() error
 }
 
 // commitManager manages a list of commits in a SQL database.
@@ -140,7 +144,16 @@ UPDATE output SET output_raw = ? WHERE commit_id = ?;
 
 // SQL statement to delete a Commit by ID.
 const deleteStmt = `
-DELETE FROM commits WHERE commit_id = ?
+DELETE FROM commits WHERE commit_id = ?;
+`
+
+// SQL statement to cancel all running Commits.
+const cancelStmt = `
+UPDATE commits SET
+commit_status = ?,
+commit_started = ?,
+commit_finished = ?
+WHERE commit_status IN ('Started', 'Pending');
 `
 
 func (db *commitManager) Find(id int64) (*Commit, error) {
@@ -215,3 +228,8 @@ func (db *commitManager) Delete(commit *Commit) error {
 	_, err := db.Exec(deleteStmt, commit.ID)
 	return err
 }
+
+func (db *commitManager) CancelAll() error {
+	_, err := db.Exec(cancelStmt, StatusKilled, time.Now().Unix(), time.Now().Unix())
+	return err
+}
diff --git a/server/resource/commit/model.go b/server/resource/commit/model.go
index fbaa2f0d..3af1bdd3 100644
--- a/server/resource/commit/model.go
+++ b/server/resource/commit/model.go
@@ -12,6 +12,7 @@ const (
 	StatusSuccess = "Success"
 	StatusFailure = "Failure"
 	StatusError   = "Error"
+	StatusKilled  = "Killed"
 )
 
 type Commit struct {