diff --git a/lib/bloom.js b/lib/bloom.js
index e123828ad0..f6d0fd03f5 100644
--- a/lib/bloom.js
+++ b/lib/bloom.js
@@ -2,20 +2,6 @@ const assert = require('assert')
 const utils = require('ethereumjs-util')
 const byteSize = 256
 
-/**
- * Drops leading zeroes from a buffer
- * @function dropLeadingZeroes
- * @param {Buffer} buff
- * @returns {Buffer} a slice of the given buffer starting at the first non-zero entry
- */
-function dropLeadingZeroes (buff) {
-  for (var i = 0; i < buff.length; i++) {
-    if (buff[i] !== 0) {
-      return buff.slice(i)
-    }
-  }
-}
-
 /**
  * Represents a Bloom
  * @constructor
@@ -36,7 +22,7 @@ var Bloom = module.exports = function (bitvector) {
  * @param {Buffer} e the element to add
  */
 Bloom.prototype.add = function (e) {
-  e = utils.keccak256(dropLeadingZeroes(e))
+  e = utils.keccak256(e)
   var mask = 2047 // binary 11111111111
 
   for (var i = 0; i < 3; i++) {
@@ -55,7 +41,7 @@ Bloom.prototype.add = function (e) {
  * @returns {boolean} Returns {@code true} if the element is in the bloom
  */
 Bloom.prototype.check = function (e) {
-  e = utils.keccak256(dropLeadingZeroes(e))
+  e = utils.keccak256(e)
   var mask = 2047 // binary 11111111111
   var match = true
 
diff --git a/lib/runBlock.js b/lib/runBlock.js
index b0bcdcbd38..603cbd9f77 100644
--- a/lib/runBlock.js
+++ b/lib/runBlock.js
@@ -36,6 +36,7 @@ module.exports = function (opts, cb) {
 
   // parse options
   const block = opts.block
+  const skipBlockValidation = opts.skipBlockValidation || false
   const generateStateRoot = !!opts.generate
   const validateStateRoot = !generateStateRoot
   const bloom = new Bloom()
@@ -80,10 +81,14 @@ module.exports = function (opts, cb) {
   }
 
   function validateBlock (cb) {
-    if (new BN(block.header.gasLimit).gte(new BN('8000000000000000', 16))) {
-      cb(new Error('Invalid block with gas limit greater than (2^63 - 1)'))
-    } else {
+    if (skipBlockValidation) {
       cb()
+    } else {
+      if (new BN(block.header.gasLimit).gte(new BN('8000000000000000', 16))) {
+        cb(new Error('Invalid block with gas limit greater than (2^63 - 1)'))
+      } else {
+        block.validate(self.blockchain, cb)
+      }
     }
   }
 
diff --git a/tests/api/bloom.js b/tests/api/bloom.js
index f52a061748..77284afd97 100644
--- a/tests/api/bloom.js
+++ b/tests/api/bloom.js
@@ -69,7 +69,7 @@ tape('bloom', (t) => {
     bloom.add(Buffer.from('0000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c48', 'hex'))
     st.equal(
       bloom.bitvector.toString('hex'),
-      '00000000000000000000080000800000000000000000000000000000000000000000000000000000000000000000000000000000000004000000080000200000000000000000000000000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000000000000000000010008000000000000000002000000000000000000000000008000000000000'
+      '00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001000081100200000000000000000000000000000000000000000000000000000000008000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000002000000000000000004000000000000000000000'
     )
     st.end()
   })
diff --git a/tests/api/runBlock.js b/tests/api/runBlock.js
index 47b8b68068..dc7ab112fb 100644
--- a/tests/api/runBlock.js
+++ b/tests/api/runBlock.js
@@ -41,7 +41,7 @@ tape('runBlock', async (t) => {
   const suite = setup()
 
   t.test('should fail without params', async (st) => {
-    suite.p.runBlock()
+    await suite.p.runBlock()
       .then(() => st.fail('should have returned error'))
       .catch((e) => st.ok(e.message.includes('invalid input'), 'correct error'))
 
@@ -49,7 +49,7 @@ tape('runBlock', async (t) => {
   })
 
   t.test('should fail without opts', async (st) => {
-    suite.p.runBlock({})
+    await suite.p.runBlock({})
       .then(() => st.fail('should have returned error'))
       .catch((e) => st.ok(e.message.includes('invalid input'), 'correct error'))
 
@@ -64,7 +64,7 @@ tape('runBlock', async (t) => {
 
     // The mocked VM uses a mocked runTx
     // which always returns an error.
-    await suite.p.runBlock({ block, root: genesis.header.stateRoot })
+    await suite.p.runBlock({ block, root: genesis.header.stateRoot, skipBlockValidation: true })
       .then(() => t.fail('should have returned error'))
       .catch((e) => t.equal(e.message, 'test'))
 
@@ -82,13 +82,27 @@ tape('should fail when block gas limit higher than 2^63-1', async (t) => {
       gasLimit: Buffer.from('8000000000000000', 16)
     }
   })
-  suite.p.runBlock({ block, root: genesis.header.stateRoot })
+  await suite.p.runBlock({ block, root: genesis.header.stateRoot })
     .then(() => t.fail('should have returned error'))
     .catch((e) => t.ok(e.message.includes('Invalid block')))
 
   t.end()
 })
 
+tape('should fail when block validation fails', async (t) => {
+  const suite = setup()
+
+  const genesis = createGenesis()
+  const block = new Block(util.rlp.decode(suite.data.blocks[0].rlp))
+  block.validate = (_, cb) => cb(new Error('test'))
+
+  await suite.p.runBlock({ block, root: genesis.header.stateRoot })
+    .then(() => t.fail('should have returned error'))
+    .catch((e) => t.ok(e.message.includes('test')))
+
+  t.end()
+})
+
 tape('should fail when tx gas limit higher than block gas limit', async (t) => {
   const suite = setup()
 
@@ -98,7 +112,7 @@ tape('should fail when tx gas limit higher than block gas limit', async (t) => {
 
   await suite.p.generateCanonicalGenesis()
 
-  await suite.p.runBlock({ block, root: genesis.header.stateRoot })
+  await suite.p.runBlock({ block, root: genesis.header.stateRoot, skipBlockValidation: true })
     .then(() => t.fail('should have returned error'))
     .catch((e) => t.ok(e.message.includes('higher gas limit')))
 
@@ -122,7 +136,9 @@ tape('should fail when runCall fails', async (t) => {
   // which always returns an error.
   // runTx is a full implementation that works.
   suite.vm.runTx = runTx
-  await suite.p.runBlock({ block, root: suite.vm.stateManager._trie.root })
+
+  await suite.p.runBlock({ block, root: suite.vm.stateManager._trie.root, skipBlockValidation: true })
+
     .then(() => t.fail('should have returned error'))
     .catch((e) => t.equal(e.message, 'test'))
 
@@ -145,7 +161,8 @@ tape('should run valid block', async (t) => {
     'genesis state root should match calculated state root'
   )
 
-  let res = await suite.p.runBlock({ block, root: suite.vm.stateManager._trie.root })
+  let res = await suite.p.runBlock({ block, root: suite.vm.stateManager._trie.root, skipBlockValidation: true })
+
   t.error(res.error, 'runBlock shouldn\'t have returned error')
   t.equal(res.results[0].gasUsed.toString('hex'), '5208', 'actual gas used should equal blockHeader gasUsed')