diff --git a/.cirrus.yml b/.cirrus.yml
index f15afca0053..7a98af89203 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -147,6 +147,10 @@ task:
     - python test\util\test_runner.py
     - python test\util\rpcauth-test.py
   functional_tests_script:
+    # Increase the dynamic port range to the maximum allowed value to mitigate "OSError: [WinError 10048] Only one usage of each socket address (protocol/network address/port) is normally permitted".
+    # See: https://docs.microsoft.com/en-us/biztalk/technical-guides/settings-that-can-be-modified-to-improve-network-performance
+    - netsh int ipv4 set dynamicport tcp start=1025 num=64511
+    - netsh int ipv6 set dynamicport tcp start=1025 num=64511
     # TODO enable '--extended' and drop '--exclude'.
     - python test\functional\test_runner.py --nocleanup --ci --quiet --combinedlogslen=4000 --jobs=4 --timeout-factor=8 --exclude %EXCLUDE_TESTS% --failfast