diff --git a/lower-constraints.txt b/lower-constraints.txt
index fb2faff12..a300da2a2 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -20,7 +20,7 @@ ddt===1.0.1
 debtcollector==1.19.0
 decorator==4.4.1
 deprecation==2.0
-doc8==0.8.1
+doc8==0.9.0
 docutils==0.14
 dogpile.cache==0.6.5
 dulwich==0.19.0
diff --git a/test-requirements.txt b/test-requirements.txt
index 5ef1d3dc8..6ae7245b3 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -6,7 +6,7 @@
 # ascii betical order.
 coverage!=4.4,>=4.0 # Apache-2.0
 ddt>=1.0.1 # MIT
-doc8>=0.8.1 # Apache-2.0
+doc8>=0.9.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD
 hacking>=4.0.0,<4.1.0 # Apache-2.0
 python-subunit>=1.0.0 # Apache-2.0/BSD