diff --git a/.cirrus.yml b/.cirrus.yml
index 2eeb4b1ff..dc7e2299a 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -25,6 +25,10 @@ task:
   compile_script:
     - make V=1
   test_script:
+    # blackhole?
+    - sysctl net.inet.tcp.blackhole
+    # make sure we don't run blackhole != 0
+    - sudo sysctl net.inet.tcp.blackhole=0
     # Some tests won't run if run as root so run them as another user.
     # Make directories world writable so the test step can write wherever it needs.
     - find . -type d -exec chmod 777 {} \;