diff --git a/requirements_py27_dev.txt b/requirements_py27_dev.txt
index 1a293f4..2ddac02 100644
--- a/requirements_py27_dev.txt
+++ b/requirements_py27_dev.txt
@@ -22,7 +22,7 @@ flake8==3.2.1
 functools32==3.2.3.post2
 future==0.16.0
 gnureadline==6.3.3
-html5lib==0.9999999
+html5lib==0.999999999
 imagesize==0.7.1
 ipykernel==4.5.2
 ipython==5.1.0
diff --git a/requirements_py3_dev.txt b/requirements_py3_dev.txt
index d1c99f0..ac2e6d0 100644
--- a/requirements_py3_dev.txt
+++ b/requirements_py3_dev.txt
@@ -19,7 +19,7 @@ entrypoints==0.2.2
 enum34==1.1.6
 flake8==3.2.1
 gnureadline==6.3.3
-html5lib==0.9999999
+html5lib==0.999999999
 imagesize==0.7.1
 ipykernel==4.5.2
 ipython==5.1.0