diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -469,6 +469,8 @@
         best_hash = [x.getbestblockhash() for x in rpc_connections]
         if best_hash.count(best_hash[0]) == len(rpc_connections):
             return
+        # Check that each peer has at least one connection
+        assert (all([len(x.getpeerinfo()) for x in rpc_connections]))
         time.sleep(wait)
     raise AssertionError("Block sync timed out:{}".format(
         "".join("\n  {!r}".format(b) for b in best_hash)))
@@ -488,6 +490,8 @@
                 for r in rpc_connections:
                     r.syncwithvalidationinterfacequeue()
             return
+        # Check that each peer has at least one connection
+        assert (all([len(x.getpeerinfo()) for x in rpc_connections]))
         time.sleep(wait)
     raise AssertionError("Mempool sync timed out:{}".format(
         "".join("\n  {!r}".format(m) for m in pool)))