diff --git a/docs/README.md b/docs/README.md
index 0d138783..62649528 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -3,7 +3,7 @@
 ### Install dependencies
 
 ```
-pip install -U recommonmark mock sphinx sphinx_rtd_theme sphinx_markdown_tables
+pip install -U recommonmark sphinx sphinx_rtd_theme sphinx_markdown_tables
 ```
 
 ### Add symlink to the root README.md
diff --git a/docs/requirements.txt b/docs/requirements.txt
index e541c2bd..fdde3077 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -3,7 +3,6 @@ Sphinx>=1.7
 recommonmark==0.4.0
 sphinx_rtd_theme
 sphinx_markdown_tables
-mock
 numpy
 iopath
 fvcore