diff --git a/tools/test-requires b/tools/test-requires
index 3d4c2d6..cba42a4 100644
--- a/tools/test-requires
+++ b/tools/test-requires
@@ -1,4 +1,8 @@
-flake8
-hacking
+# Install bounded pep8/pyflakes first, then let flake8 install
+pep8==1.4.5
+pyflakes==0.7.2
+flake8==2.0
+hacking>=0.5.3,<0.6
+#
 #TODO(afazekas): ensure pg_config installed
 psycopg2