diff --git a/build/main.go b/build/main.go
index f4942cb7b7..498272e27f 100644
--- a/build/main.go
+++ b/build/main.go
@@ -217,6 +217,11 @@ type Thresholds struct {
 	High   *uint32
 }
 
+type Timebounds struct {
+    MinTime uint64
+    MaxTime uint64
+}
+
 // Trustor is a mutator capable of setting the trustor on
 // allow_trust operation.
 type Trustor struct {
diff --git a/build/transaction.go b/build/transaction.go
index b175c01e70..538a897670 100644
--- a/build/transaction.go
+++ b/build/transaction.go
@@ -256,6 +256,11 @@ func (m MemoText) MutateTransaction(o *TransactionBuilder) (err error) {
 	return
 }
 
+func (m Timebounds) MutateTransaction(o *TransactionBuilder) error {
+    o.TX.TimeBounds = &xdr.TimeBounds{MinTime: xdr.Uint64(m.MinTime), MaxTime: xdr.Uint64(m.MaxTime)}
+    return nil
+}
+
 // MutateTransaction for Network sets the Network ID to use when signing this transaction
 func (m Network) MutateTransaction(o *TransactionBuilder) error {
 	o.NetworkPassphrase = m.Passphrase
diff --git a/build/transaction_test.go b/build/transaction_test.go
index 22c50dd78c..144f3c4e8c 100644
--- a/build/transaction_test.go
+++ b/build/transaction_test.go
@@ -111,6 +111,15 @@ var _ = Describe("Transaction Mutators:", func() {
 		})
 	})
 
+    Describe("Timebounds", func() {
+        BeforeEach(func() { mut = Timebounds{1521056118, 1521056298} })
+        It("succeeds", func() { Expect(err).NotTo(HaveOccurred()) })
+        It("sets an minimum and maximum timebound on the transaction", func() {
+            Expect(subject.TX.TimeBounds.MinTime).To(Equal(xdr.Uint64(1521056118)))
+            Expect(subject.TX.TimeBounds.MaxTime).To(Equal(xdr.Uint64(1521056298)))
+        })
+    })
+
 	Describe("AllowTrustBuilder", func() {
 		BeforeEach(func() { mut = AllowTrust() })
 		It("adds itself to the tx's operations", func() {