diff --git a/.gitignore b/.gitignore
index 8a870e0..bf1a504 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,3 +11,4 @@
 *.egg
 .eggs/
 *.py[co]
+./hypothesis
diff --git a/dev-requirements.txt b/dev-requirements.txt
index 440d3b0..55aebd4 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -12,5 +12,7 @@
 sphinxcontrib-spelling
 tox
 twine
+hypothesis
+hypothesis-pytest
 -e .
 -e vectors
diff --git a/setup.py b/setup.py
index b36f3de..ea2ea18 100644
--- a/setup.py
+++ b/setup.py
@@ -62,6 +62,10 @@
     "iso8601",
 ]
 
+if sys.version_info[:2] == (2, 6):
+    test_requirements.append("hypothesis")
+    test_requirements.append("hypothesis-pytest")
+
 # If there's no vectors locally that probably means we are in a tarball and
 # need to go and get the matching vectors package from PyPi
 if not os.path.exists(os.path.join(base_dir, "vectors/setup.py")):
diff --git a/tox.ini b/tox.ini
index a890e38..1c15abf 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,6 +8,29 @@
     iso8601
     pretend
     pytest<2.8
+    hypothesis
+    hypothesis-pytest
+    ./vectors
+passenv = ARCHFLAGS LDFLAGS CFLAGS INCLUDE LIB LD_LIBRARY_PATH USERNAME
+commands =
+    pip list
+    python -c "from cryptography.hazmat.backends.openssl.backend import backend; print(backend.openssl_version_text())"
+    # We use parallel mode and then combine here so that coverage.py will take
+    # the paths like .tox/py34/lib/python3.4/site-packages/cryptography/__init__.py
+    # and collapse them into src/cryptography/__init__.py.
+    coverage run --parallel-mode -m pytest --capture=no --strict {posargs}
+    coverage combine
+    coverage report -m
+
+[testenv:py26]
+# This mirrors the testenv minus the hypothesis and hypothesis-test deps.
+deps =
+    coverage
+    iso8601
+    pretend
+    pytest<2.8
+    hypothesis
+    hypothesis-pytest
     ./vectors
 passenv = ARCHFLAGS LDFLAGS CFLAGS INCLUDE LIB LD_LIBRARY_PATH USERNAME
 commands =
@@ -85,7 +108,7 @@
     py.test --capture=no --strict --random {posargs}
 
 [flake8]
-exclude = .tox,*.egg,.git,_build
+exclude = .tox,*.egg,.git,_build,.hypothesis
 select = E,W,F,N,I
 application-import-names = cryptography,cryptography_vectors,tests