diff --git a/src/_zkapauthorizer/tests/__init__.py b/src/_zkapauthorizer/tests/__init__.py
index 7bee673d66603b08e562dd9c149a9785c7e12faf..1fd9a9da7f721537646cd78176a3c063909b2101 100644
--- a/src/_zkapauthorizer/tests/__init__.py
+++ b/src/_zkapauthorizer/tests/__init__.py
@@ -44,10 +44,12 @@ def _configure_hypothesis():
 
     settings.register_profile(
         "big",
-        max_examples=100000,
+        max_examples=10000,
+        deadline=None,
     )
 
     profile_name = environ.get("ZKAPAUTHORIZER_HYPOTHESIS_PROFILE", "default")
     settings.load_profile(profile_name)
+    print("Loaded profile {}".format(profile_name))
 
 _configure_hypothesis()
diff --git a/zkapauthorizer.nix b/zkapauthorizer.nix
index ae7453630fde5af7ae11afb728cdd9563f109f8c..6572ed3005acd776bb983aee9dc33488dcbfab0b 100644
--- a/zkapauthorizer.nix
+++ b/zkapauthorizer.nix
@@ -1,7 +1,7 @@
 { buildPythonPackage, sphinx, circleci-cli
 , attrs, zope_interface, twisted, tahoe-lafs, privacypass
 , fixtures, testtools, hypothesis, pyflakes, treq, coverage
-, hypothesisProfile ? null
+, hypothesisProfile ? "default"
 , collectCoverage ? false
 }:
 buildPythonPackage rec {
@@ -34,10 +34,12 @@ buildPythonPackage rec {
     treq
   ];
 
+
+
   checkPhase = ''
     runHook preCheck
     "${pyflakes}/bin/pyflakes" src/_zkapauthorizer
-    python -m ${if collectCoverage
+    ZKAPAUTHORIZER_HYPOTHESIS_PROFILE=${hypothesisProfile} python -m ${if collectCoverage
       then "coverage run --branch --source _zkapauthorizer,twisted.plugins.zkapauthorizer --module"
       else ""
     } twisted.trial _zkapauthorizer