diff --git a/test/mempool-test.js b/test/mempool-test.js
index 00335016..335b35de 100644
--- a/test/mempool-test.js
+++ b/test/mempool-test.js
@@ -141,6 +141,76 @@ describe('Mempool', function() {
     });
   });
 
+  it('should handle locktime', function(cb) {
+    var w = new bcoin.wallet();
+
+    // Coinbase
+    var t1 = bcoin.mtx().addOutput(w, 50000).addOutput(w, 10000); // 10000 instead of 1000
+    var prev = new bcoin.script([w.publicKey, opcodes.OP_CHECKSIG]);
+    var prevHash = bcoin.ec.random(32).toString('hex');
+    var dummyInput = {
+      prevout: {
+        hash: prevHash,
+        index: 0
+      },
+      coin: {
+        version: 1,
+        height: 0,
+        value: 70000,
+        script: prev,
+        coinbase: false,
+        hash: prevHash,
+        index: 0
+      },
+      script: new bcoin.script([]),
+      sequence: 0xffffffff
+    };
+    t1.addInput(dummyInput);
+    t1.setLocktime(200);
+    chain.tip.height = 200;
+    t1.inputs[0].script = new bcoin.script([t1.createSignature(0, prev, w.privateKey, 'all', 0)]),
+    mempool.addTX(t1, function(err) {
+      chain.tip.height = 0;
+      assert.ifError(err);
+      cb();
+    });
+  });
+
+  it('should handle invalid locktime', function(cb) {
+    var w = new bcoin.wallet();
+
+    // Coinbase
+    var t1 = bcoin.mtx().addOutput(w, 50000).addOutput(w, 10000); // 10000 instead of 1000
+    var prev = new bcoin.script([w.publicKey, opcodes.OP_CHECKSIG]);
+    var prevHash = bcoin.ec.random(32).toString('hex');
+    var dummyInput = {
+      prevout: {
+        hash: prevHash,
+        index: 0
+      },
+      coin: {
+        version: 1,
+        height: 0,
+        value: 70000,
+        script: prev,
+        coinbase: false,
+        hash: prevHash,
+        index: 0
+      },
+      script: new bcoin.script([]),
+      sequence: 0xffffffff
+    };
+    t1.addInput(dummyInput);
+    t1.setLocktime(200);
+    chain.tip.height = 200 - 1;
+    t1.inputs[0].script = new bcoin.script([t1.createSignature(0, prev, w.privateKey, 'all', 0)]),
+    mempool.addTX(t1, function(err) {
+      chain.tip.height = 0;
+      assert(err);
+      cb();
+    });
+  });
+
   it('should destroy mempool', function(cb) {
     mempool.close(cb);
   });