diff --git a/conftest.py b/conftest.py
new file mode 100644
--- /dev/null
+++ b/conftest.py
@@ -0,0 +1,6 @@
+from hypothesis import settings
+
+# define tests profile. Full documentation is at:
+# https://hypothesis.readthedocs.io/en/latest/settings.html#settings-profiles
+settings.register_profile("fast", max_examples=5, deadline=5000)
+settings.register_profile("slow", max_examples=20, deadline=5000)
diff --git a/tox.ini b/tox.ini
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,16 @@
   LC_CTYPE=C.UTF-8
   LANG=C.UTF-8
 commands =
-  pifpaf run postgresql -- pytest --cov=swh --cov-branch {posargs}
+  pifpaf run postgresql -- pytest --hypothesis-profile=fast --cov=swh --cov-branch {posargs}
+
+[testenv:py3-slow]
+deps =
+  .[testing]
+  pytest-cov
+  pifpaf
+commands =
+  pifpaf run postgresql -- pytest --hypothesis-profile=slow --cov=swh --cov-branch {posargs}
+
 
 [testenv:flake8]
 skip_install = true