diff --git a/requirements.txt b/requirements.txt
index a3c1d8a..ee867b6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,10 +1,10 @@
-pbr>=0.5.21,<1.0
+pbr>=0.6,!=0.7,<1.0
 
 # never put a cap on this, *ever*, sqla versions are handled via
 # tox, and if SQLA is capped it will only make it so we aren't testing
 # against all the versions we are compatible with.
-SQLAlchemy>=0.7.8
+SQLAlchemy>=0.7.8,!=0.9.5,<=0.9.99
 decorator
-six>=1.4.1
+six>=1.7.0
 sqlparse
-Tempita >= 0.4
+Tempita>=0.4