diff --git a/bitcoin/composite.py b/bitcoin/composite.py
index 87a69972..823374f2 100644
--- a/bitcoin/composite.py
+++ b/bitcoin/composite.py
@@ -45,7 +45,7 @@ def preparemultitx(frm, *args, **kwargs):
     u = unspent(frm, **kwargs)
     u2 = select(u, int(outvalue)+int(fee))
     argz = u2 + outs + [frm, fee]
-    return mksend(*argz)
+    return mksend(*argz, **kwargs)
 
 
 # BIP32 hierarchical deterministic multisig script
diff --git a/bitcoin/transaction.py b/bitcoin/transaction.py
index e3728b8a..82dd6a7c 100644
--- a/bitcoin/transaction.py
+++ b/bitcoin/transaction.py
@@ -9,7 +9,7 @@
 def json_is_base(obj, base):
     if not is_python2 and isinstance(obj, bytes):
         return False
-    
+
     alpha = get_code_string(base)
     if isinstance(obj, string_types):
         for i in range(len(obj)):
@@ -58,7 +58,7 @@ def read_as_int(bytez):
 
     def read_var_int():
         pos[0] += 1
-        
+
         val = from_byte_to_int(tx[pos[0]-1])
         if val < 253:
             return val
@@ -300,7 +300,7 @@ def serialize_script(script):
         if json_is_base(script, 16):
             return safe_hexlify(serialize_script(json_changebase(script,
                                     lambda x: binascii.unhexlify(x))))
-        
+
         result = bytes()
         for b in map(serialize_script_unit, script):
             result += b if isinstance(b, bytes) else bytes(b, 'utf-8')
@@ -387,7 +387,7 @@ def is_inp(arg):
     return len(arg) > 64 or "output" in arg or "outpoint" in arg
 
 
-def mktx(*args):
+def mktx(*args, **kwargs):
     # [in0, in1...],[out0, out1...] or in0, in1 ... out0 out1 ...
     ins, outs = [], []
     for arg in args:
@@ -396,7 +396,7 @@ def mktx(*args):
         else:
             (ins if is_inp(arg) else outs).append(arg)
 
-    txobj = {"locktime": 0, "version": 1, "ins": [], "outs": []}
+    txobj = {"locktime": kwargs.get('locktime', 0), "version": 1, "ins": [], "outs": []}
     for i in ins:
         if isinstance(i, dict) and "outpoint" in i:
             txobj["ins"].append(i)
@@ -451,7 +451,7 @@ def select(unspent, value):
 # Only takes inputs of the form { "output": blah, "value": foo }
 
 
-def mksend(*args):
+def mksend(*args, **kwargs):
     argz, change, fee = args[:-2], args[-2], int(args[-1])
     ins, outs = [], []
     for arg in argz:
@@ -479,4 +479,4 @@ def mksend(*args):
     elif isum > osum+fee+5430:
         outputs2 += [{"address": change, "value": isum-osum-fee}]
 
-    return mktx(ins, outputs2)
+    return mktx(ins, outputs2, **kwargs)
diff --git a/test.py b/test.py
index 2cf415d8..a6e7baa2 100644
--- a/test.py
+++ b/test.py
@@ -210,9 +210,11 @@ def test_all(self):
         addresses = [pubtoaddr(pub) for pub in pubs]
         mscript = mk_multisig_script(pubs[1:], 2, 3)
         msigaddr = p2sh_scriptaddr(mscript)
-        tx = mktx(['01'*32+':1', '23'*32+':2'], [msigaddr+':20202', addresses[0]+':40404'])
+        tx = mktx(['01'*32+':1', '23'*32+':2'], [msigaddr+':20202', addresses[0]+':40404'], locktime=2222222222)
         tx1 = sign(tx, 1, privs[0])
 
+        self.assertEqual(deserialize(tx)['locktime'], 2222222222, "Locktime incorrect")
+
         sig1 = multisign(tx, 0, mscript, privs[1])
         self.assertTrue(verify_tx_input(tx1, 0, mscript, sig1, pubs[1]), "Verification Error")
 
@@ -236,6 +238,16 @@ def test_multisig(self):
         self.assertEqual(p2sh_scriptaddr(script, 0xc4), "2MuABMvWTgpZRd4tAG25KW6YzvcoGVZDZYP")
         self.assertEqual(p2sh_scriptaddr(script, 196), "2MuABMvWTgpZRd4tAG25KW6YzvcoGVZDZYP")
 
+    def test_preparetx(self):
+        hextx = preparetx('12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX', '1HLoD9E4SDFFPDiYfNYnkBLQ85Y51J3Zb1', 13)
+        tx = deserialize(hextx)
+        self.assertEqual(tx['locktime'], 0, "Locktime incorrect")
+        self.assertEqual(tx['outs'][0]['value'], 13, "Value incorrect")
+
+        hextx = preparetx('12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX', '1HLoD9E4SDFFPDiYfNYnkBLQ85Y51J3Zb1', 13, locktime=2222222222)
+        tx = deserialize(hextx)
+        self.assertEqual(tx['locktime'], 2222222222, "Locktime incorrect")
+        self.assertEqual(tx['outs'][0]['value'], 13, "Value incorrect")
 
 class TestDeterministicGenerate(unittest.TestCase):
     @classmethod