diff --git a/src/_zkapauthorizer/tests/test_tahoe.py b/src/_zkapauthorizer/tests/test_tahoe.py
index 9df8156d26fdf67dbf13d710bfeb8d87cec0ffbe..ad2846ef0bedb35a7c3c07925206b4d06212faae 100644
--- a/src/_zkapauthorizer/tests/test_tahoe.py
+++ b/src/_zkapauthorizer/tests/test_tahoe.py
@@ -188,6 +188,7 @@ class TahoeStorageManager(TestResourceManager):
         Kill the storage node child process.
         """
         storage.process.kill()
+        storage.process.wait()
 
     def make(self, dependency_resources):
         """
@@ -289,6 +290,7 @@ class TahoeClientManager(TestResourceManager):
         Kill the client node child process.
         """
         client.process.kill()
+        client.process.wait()
 
     def make(self, dependency_resources):
         """