diff --git a/requirements.txt b/requirements.txt
index e93d264..b4d8e81 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,8 @@ argcomplete
 # GitPython 1.0.1 required by openstack global-requirements
 # python>=3 should work with >=0.3.4
 # python<3 should work with >=0.3.2.RC1,!=0.3.2
-GitPython>=1.0.1 # BSD License (3 clause)
+GitPython>=1.0.1,<2.1.12;python_version<'3.0'  # BSD License (3 clause)
+GitPython>=1.0.1;python_version>='3.0'  # BSD License (3 clause)
 # pbr 1.6 or newer required by openstack global-requirements
 # >= 1.0.0 should be sufficient for compatibility
 pbr>=1.6 # Apache-2.0
diff --git a/test-requirements.txt b/test-requirements.txt
index 8e554d6..9317ecb 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,8 +1,8 @@
 hacking>=0.11.0,<0.12  # Apache-2.0
 faker>=0.8.16
 mock>=2.0.0
-sphinx>=1.5.1,<2.0.0;python_version=='2.7'  # BSD
-sphinx>=1.5.1;python_version>='3.4'  # BSD
+sphinx>=1.5.1,!=1.6.6,!=1.6.7,<2.0.0;python_version=='2.7'  # BSD
+sphinx>=1.5.1,!=1.6.6,!=1.6.7,!=2.1.0;python_version>='3.4'  # BSD
 coverage>=3.6  # Apache-2.0
 fixtures>=0.3.14
 python-subunit>=1.3.0