diff --git a/test/functional/p2p_invalid_block.py b/test/functional/p2p_invalid_block.py
index edcade63c1..f6f060a9ea 100755
--- a/test/functional/p2p_invalid_block.py
+++ b/test/functional/p2p_invalid_block.py
@@ -10,20 +10,17 @@ In this test we connect to one node over p2p, and test block requests:
 3) Invalid block with bad coinbase value should be rejected and not
 re-requested.
 """
-
-from test_framework.test_framework import ComparisonTestFramework
-from test_framework.util import *
-from test_framework.comptool import TestManager, TestInstance, RejectResult
-from test_framework.blocktools import *
-from test_framework.mininode import network_thread_start
 import copy
 import time
 
-# Use the ComparisonTestFramework with 1 node: only use --testbinary.
-class InvalidBlockRequestTest(ComparisonTestFramework):
+from test_framework.blocktools import create_block, create_coinbase, create_transaction
+from test_framework.comptool import RejectResult, TestInstance, TestManager
+from test_framework.messages import COIN
+from test_framework.mininode import network_thread_start
+from test_framework.test_framework import ComparisonTestFramework
+from test_framework.util import assert_equal
 
-    ''' Can either run this test as 1 node with expected answers, or two and compare them. 
-        Change the "outcome" variable from each TestInstance object to only do the comparison. '''
+class InvalidBlockRequestTest(ComparisonTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
         self.setup_clean_chain = True
@@ -39,11 +36,10 @@ class InvalidBlockRequestTest(ComparisonTestFramework):
     def get_tests(self):
         if self.tip is None:
             self.tip = int("0x" + self.nodes[0].getbestblockhash(), 0)
-        self.block_time = int(time.time())+1
+        self.block_time = int(time.time()) + 1
+
+        self.log.info("Create a new block with an anyone-can-spend coinbase")
 
-        '''
-        Create a new block with an anyone-can-spend coinbase
-        '''
         height = 1
         block = create_block(self.tip, create_coinbase(height), self.block_time)
         self.block_time += 1
@@ -54,9 +50,8 @@ class InvalidBlockRequestTest(ComparisonTestFramework):
         height += 1
         yield TestInstance([[block, True]])
 
-        '''
-        Now we need that block to mature so we can spend the coinbase.
-        '''
+        self.log.info("Mature the block.")
+
         test = TestInstance(sync_every_block=False)
         for i in range(100):
             block = create_block(self.tip, create_coinbase(height), self.block_time)
@@ -67,13 +62,12 @@ class InvalidBlockRequestTest(ComparisonTestFramework):
             height += 1
         yield test
 
-        '''
-        Now we use merkle-root malleability to generate an invalid block with
-        same blockheader.
-        Manufacture a block with 3 transactions (coinbase, spend of prior
-        coinbase, spend of that spend).  Duplicate the 3rd transaction to 
-        leave merkle root and blockheader unchanged but invalidate the block.
-        '''
+        # Use merkle-root malleability to generate an invalid block with
+        # same blockheader.
+        # Manufacture a block with 3 transactions (coinbase, spend of prior
+        # coinbase, spend of that spend).  Duplicate the 3rd transaction to
+        # leave merkle root and blockheader unchanged but invalidate the block.
+        self.log.info("Test merkle root malleability.")
         block2 = create_block(self.tip, create_coinbase(height), self.block_time)
         self.block_time += 1
 
@@ -98,13 +92,12 @@ class InvalidBlockRequestTest(ComparisonTestFramework):
         yield TestInstance([[block2, RejectResult(16, b'bad-txns-duplicate')], [block2_orig, True]])
         height += 1
 
-        '''
-        Make sure that a totally screwed up block is not valid.
-        '''
+        self.log.info("Test very broken block.")
+
         block3 = create_block(self.tip, create_coinbase(height), self.block_time)
         self.block_time += 1
-        block3.vtx[0].vout[0].nValue = 100 * COIN # Too high!
-        block3.vtx[0].sha256=None
+        block3.vtx[0].vout[0].nValue = 100 * COIN  # Too high!
+        block3.vtx[0].sha256 = None
         block3.vtx[0].calc_sha256()
         block3.hashMerkleRoot = block3.calc_merkle_root()
         block3.rehash()