diff --git a/test/functional/p2p_invalid_block.py b/test/functional/p2p_invalid_block.py
--- a/test/functional/p2p_invalid_block.py
+++ b/test/functional/p2p_invalid_block.py
@@ -91,7 +91,7 @@
         assert(block2_orig.vtx != block2.vtx)
 
         node.p2p.send_blocks_and_test(
-            [block2], node, success=False, request_block=False, reject_code=16, reject_reason=b'bad-txns-duplicate')
+            [block2], node, success=False, request_block=False, reject_reason='bad-txns-duplicate')
 
         # Check transactions for duplicate inputs
         self.log.info("Test duplicate input block.")
@@ -104,7 +104,7 @@
         block2_orig.rehash()
         block2_orig.solve()
         node.p2p.send_blocks_and_test(
-            [block2_orig], node, success=False, request_block=False, reject_code=16, reject_reason=b'bad-txns-inputs-duplicate')
+            [block2_orig], node, success=False, request_block=False, reject_reason='bad-txns-inputs-duplicate')
 
         self.log.info("Test very broken block.")
 
@@ -118,7 +118,7 @@
         block3.solve()
 
         node.p2p.send_blocks_and_test(
-            [block3], node, success=False, request_block=False, reject_code=16, reject_reason=b'bad-cb-amount')
+            [block3], node, success=False, request_block=False, reject_reason='bad-cb-amount')
 
 
 if __name__ == '__main__':