diff --git a/nfv/tox.ini b/nfv/tox.ini
index e63d46d5..8965e3da 100755
--- a/nfv/tox.ini
+++ b/nfv/tox.ini
@@ -94,7 +94,7 @@ skip_install = True
 deps =
     hacking
     flake8-bugbear
-    flake8
+    flake8<3.6.0
 commands =
     flake8 {[nfv]nfv_base_dir}
 
diff --git a/nova-api-proxy/tox.ini b/nova-api-proxy/tox.ini
index b0bf8d0c..1353683b 100644
--- a/nova-api-proxy/tox.ini
+++ b/nova-api-proxy/tox.ini
@@ -46,7 +46,7 @@ skip_install = True
 deps =
     hacking
     flake8-bugbear
-    flake8
+    flake8<3.6.0
 commands =
     flake8