diff --git a/test/functional/p2p_sendheaders.py b/test/functional/p2p_sendheaders.py
index 6ddb00185..2c8146ec0 100755
--- a/test/functional/p2p_sendheaders.py
+++ b/test/functional/p2p_sendheaders.py
@@ -493,7 +493,7 @@ class SendHeadersTest(BitcoinTestFramework):
 
         # Now announce a header that forks the last two blocks
         tip = blocks[0].sha256
-        height -= 1
+        height -= 2
         blocks = []
 
         # Create extra blocks for later
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index 80da215fc..f9b592d19 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -358,7 +358,7 @@ def connect_nodes_bi(nodes, a, b):
     connect_nodes(nodes[a], b)
     connect_nodes(nodes[b], a)
 
-def sync_blocks(rpc_connections, *, wait=1, timeout=60):
+def sync_blocks(rpc_connections, *, wait=1, timeout=600):
     """
     Wait until everybody has the same tip.