diff --git a/lower-constraints.txt b/lower-constraints.txt
index b7d718268..43781ff72 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -1,10 +1,11 @@
-alembic==0.8.10
+alembic==0.9.6
 autobahn==20.7.1
 Babel==2.3.4
 coverage==4.0
-cryptography==2.1
+cryptography==2.7
 ddt==1.0.1
-doc8==0.6.0
+doc8==0.8.1
+docutils==0.15.2
 dogpile.cache==1.0.2
 enum34==1.0.4;python_version=='2.7'
 falcon==1.1.0
@@ -60,7 +61,7 @@ testresources==2.0.0
 testscenarios==0.4
 testtools==2.2.0
 trollius==2.1;python_version=='2.7'
-txaio==2.8.2
+txaio==20.3.1
 urllib3==1.21.1
 WebOb==1.7.1
 websocket-client==0.44.0
diff --git a/requirements.txt b/requirements.txt
index 693ba508b..cb5940f30 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,9 +3,9 @@
 # process, which may cause wedges in the gate later.
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 
-alembic>=0.8.10 # MIT
+alembic>=0.9.6 # MIT
 Babel!=2.4.0,>=2.3.4 # BSD
-cryptography>=2.1 # BSD/Apache-2.0
+cryptography>=2.7 # BSD/Apache-2.0
 falcon>=1.1.0 # Apache-2.0
 jsonschema>=3.2.0 # MIT
 iso8601>=0.1.11 # MIT
diff --git a/test-requirements.txt b/test-requirements.txt
index 131715e56..91e1c1535 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -16,9 +16,9 @@ PyMySQL>=0.8.0 # MIT License
 
 # Unit testing
 coverage!=4.4,>=4.0 # Apache-2.0
-cryptography>=2.1 # BSD/Apache-2.0
+cryptography>=2.7 # BSD/Apache-2.0
 ddt>=1.0.1 # MIT
-doc8>=0.6.0 # Apache-2.0
+doc8>=0.8.1 # Apache-2.0
 Pygments>=2.2.0 # BSD license
 fixtures>=3.0.0 # Apache-2.0/BSD
 
diff --git a/tox.ini b/tox.ini
index e6a224b2f..f9d53ce64 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,10 @@
 [tox]
-minversion = 2.0
-envlist = py37,pep8
+minversion = 3.1.0
+envlist = py3,pep8
 skipsdist = True
+# this allows tox to infer the base python from the environment name
+# and override any basepython configured in this file
+ignore_basepython_conflict=true
 
 [testenv]
 basepython = python3
@@ -116,6 +119,5 @@ paths = ./zaqar/hacking
 
 [testenv:lower-constraints]
 deps =
-  -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt