diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -413,7 +413,8 @@
 
             # Create cache directories, run bitcoinds:
             for i in range(MAX_NODES):
-                datadir = initialize_datadir(self.options.cachedir, i)
+                datadir = initialize_datadir(
+                    self.options.cachedir, i, p2p_port(i), rpc_port(i))
                 args = [os.getenv("BITCOIND", "bitcoind"), "-server",
                         "-keypool=1", "-datadir=" + datadir, "-discover=0"]
                 if i > 0:
@@ -460,7 +461,8 @@
             to_dir = os.path.join(self.options.tmpdir, "node" + str(i))
             shutil.copytree(from_dir, to_dir)
             # Overwrite port/rpcport in bitcoin.conf
-            initialize_datadir(self.options.tmpdir, i)
+            initialize_datadir(self.options.tmpdir, i,
+                               p2p_port(i), rpc_port(i))
 
     def _initialize_chain_clean(self):
         """Initialize empty blockchain for use by the test.
@@ -468,7 +470,8 @@
         Create an empty blockchain and num_nodes wallets.
         Useful if a test case wants complete control over initialization."""
         for i in range(self.num_nodes):
-            initialize_datadir(self.options.tmpdir, i)
+            initialize_datadir(self.options.tmpdir, i,
+                               p2p_port(i), rpc_port(i))
 
 
 class ComparisonTestFramework(BitcoinTestFramework):
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
@@ -326,14 +326,14 @@
 ################
 
 
-def initialize_datadir(dirname, n):
+def initialize_datadir(dirname, n, p2p_port, rpc_port):
     datadir = os.path.join(dirname, "node" + str(n))
     if not os.path.isdir(datadir):
         os.makedirs(datadir)
     with open(os.path.join(datadir, "bitcoin.conf"), 'w', encoding='utf8') as f:
         f.write("regtest=1\n")
-        f.write("port=" + str(p2p_port(n)) + "\n")
-        f.write("rpcport=" + str(rpc_port(n)) + "\n")
+        f.write("port=" + str(p2p_port) + "\n")
+        f.write("rpcport=" + str(rpc_port) + "\n")
         f.write("listenonion=0\n")
         f.write("usecashaddr=1\n")
     return datadir