diff --git a/test/functional/p2p-segwit.py b/test/functional/p2p-segwit.py
index 943bc2c6d..a9ef47559 100755
--- a/test/functional/p2p-segwit.py
+++ b/test/functional/p2p-segwit.py
@@ -32,8 +32,8 @@ def get_virtual_size(witness_block):
     return vsize
 
 class TestNode(NodeConnCB):
-    def set_test_params(self):
-        self.num_nodes = 3
+    def __init__(self):
+        super().__init__()
         self.getdataset = set()
 
     def on_getdata(self, conn, message):
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index abed661f3..d072969d7 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -1502,6 +1502,7 @@ class NodeConnCB(object):
             except:
                 print("ERROR delivering %s (%s)" % (repr(message),
                                                     sys.exc_info()[0]))
+                raise
 
     def get_deliver_sleep_time(self):
         with mininode_lock:
@@ -1702,13 +1703,10 @@ class NodeConn(asyncore.dispatcher):
         self.cb.on_close(self)
 
     def handle_read(self):
-        try:
-            t = self.recv(8192)
-            if len(t) > 0:
-                self.recvbuf += t
-                self.got_data()
-        except:
-            pass
+        t = self.recv(8192)
+        if len(t) > 0:
+            self.recvbuf += t
+            self.got_data()
 
     def readable(self):
         return True
@@ -1774,8 +1772,10 @@ class NodeConn(asyncore.dispatcher):
                     self.got_message(t)
                 else:
                     logger.warning("Received unknown command from %s:%d: '%s' %s" % (self.dstaddr, self.dstport, command, repr(msg)))
+                    raise ValueError("Unknown command: '%s'" % (command))
         except Exception as e:
             logger.exception('got_data:', repr(e))
+            raise
 
     def send_message(self, message, pushbuf=False):
         if self.state != "connected" and not pushbuf: