diff --git a/qa/pull-tester/rpc-tests.py b/qa/pull-tester/rpc-tests.py
index 1e630a340..3f0660981 100755
--- a/qa/pull-tester/rpc-tests.py
+++ b/qa/pull-tester/rpc-tests.py
@@ -282,9 +282,10 @@ class RPCTestHandler:
             # Add tests
             self.num_running += 1
             t = self.test_list.pop(0)
+            port_seed = ["--portseed=%s" % len(self.test_list)]
             self.jobs.append((t,
                               time.time(),
-                              subprocess.Popen((RPC_TESTS_DIR + t).split() + self.flags,
+                              subprocess.Popen((RPC_TESTS_DIR + t).split() + self.flags + port_seed,
                                                universal_newlines=True,
                                                stdout=subprocess.PIPE,
                                                stderr=subprocess.PIPE)))
diff --git a/qa/rpc-tests/test_framework/test_framework.py b/qa/rpc-tests/test_framework/test_framework.py
index b1ac8e8fe..a8a3da5e8 100755
--- a/qa/rpc-tests/test_framework/test_framework.py
+++ b/qa/rpc-tests/test_framework/test_framework.py
@@ -5,10 +5,10 @@
 
 # Base class for RPC testing
 
-# Add python-bitcoinrpc to module search path:
+import logging
+import optparse
 import os
 import sys
-
 import shutil
 import tempfile
 import traceback
@@ -26,6 +26,7 @@ from .util import (
     enable_coverage,
     check_json_precision,
     initialize_chain_clean,
+    PortSeed,
 )
 
 
@@ -95,7 +96,6 @@ class BitcoinTestFramework(object):
         self.setup_network(False)
 
     def main(self):
-        import optparse
 
         parser = optparse.OptionParser(usage="%prog [options]")
         parser.add_option("--nocleanup", dest="nocleanup", default=False, action="store_true",
@@ -108,18 +108,21 @@ class BitcoinTestFramework(object):
                           help="Root directory for datadirs")
         parser.add_option("--tracerpc", dest="trace_rpc", default=False, action="store_true",
                           help="Print out all RPC calls as they are made")
+        parser.add_option("--portseed", dest="port_seed", default=os.getpid(), type='int',
+                          help="The seed to use for assigning port numbers (default: current process id)")
         parser.add_option("--coveragedir", dest="coveragedir",
                           help="Write tested RPC commands into this directory")
         self.add_options(parser)
         (self.options, self.args) = parser.parse_args()
 
         if self.options.trace_rpc:
-            import logging
             logging.basicConfig(level=logging.DEBUG, stream=sys.stdout)
 
         if self.options.coveragedir:
             enable_coverage(self.options.coveragedir)
 
+        PortSeed.n = self.options.port_seed
+
         os.environ['PATH'] = self.options.srcdir+":"+os.environ['PATH']
 
         check_json_precision()
diff --git a/qa/rpc-tests/test_framework/util.py b/qa/rpc-tests/test_framework/util.py
index c1785f062..f05a2edd5 100644
--- a/qa/rpc-tests/test_framework/util.py
+++ b/qa/rpc-tests/test_framework/util.py
@@ -8,7 +8,6 @@
 # Helpful routines for regression testing
 #
 
-# Add python-bitcoinrpc to module search path:
 import os
 import sys
 
@@ -46,6 +45,11 @@ PORT_MIN = 11000
 # The number of ports to "reserve" for p2p and rpc, each
 PORT_RANGE = 5000
 
+
+class PortSeed:
+    # Must be initialized with a unique integer for each process
+    n = None
+
 def enable_coverage(dirname):
     """Maintain a log of which RPC calls are made during testing."""
     global COVERAGE_DIR
@@ -80,10 +84,10 @@ def get_rpc_proxy(url, node_number, timeout=None):
 
 def p2p_port(n):
     assert(n <= MAX_NODES)
-    return PORT_MIN + n + (MAX_NODES * os.getpid()) % (PORT_RANGE - 1 - MAX_NODES)
+    return PORT_MIN + n + (MAX_NODES * PortSeed.n) % (PORT_RANGE - 1 - MAX_NODES)
 
 def rpc_port(n):
-    return PORT_MIN + PORT_RANGE + n + (MAX_NODES * os.getpid()) % (PORT_RANGE -1 - MAX_NODES)
+    return PORT_MIN + PORT_RANGE + n + (MAX_NODES * PortSeed.n) % (PORT_RANGE - 1 - MAX_NODES)
 
 def check_json_precision():
     """Make sure json library being used does not lose precision converting BTC values"""