diff --git a/Hub/Dockerfile b/Hub/Dockerfile
index 24f55bd9d1..f8b4c880d0 100644
--- a/Hub/Dockerfile
+++ b/Hub/Dockerfile
@@ -16,7 +16,7 @@ ENV GRID_NEW_SESSION_WAIT_TIMEOUT -1
 ENV GRID_JETTY_MAX_THREADS -1
 ENV GRID_NODE_POLLING  5000
 ENV GRID_CLEAN_UP_CYCLE 5000
-ENV GRID_TIMEOUT 30000
+ENV GRID_TIMEOUT 30
 ENV GRID_BROWSER_TIMEOUT 0
 ENV GRID_MAX_SESSION 5
 ENV GRID_UNREGISTER_IF_STILL_DOWN_AFTER 30000
diff --git a/Hub/Dockerfile.txt b/Hub/Dockerfile.txt
index 56bd474d61..da4ac1b2e6 100644
--- a/Hub/Dockerfile.txt
+++ b/Hub/Dockerfile.txt
@@ -7,13 +7,19 @@ MAINTAINER Selenium <selenium-developers@googlegroups.com>
 EXPOSE 4444
 
 ENV GRID_THROW_ON_CAPABILITY_NOT_PRESENT true
+# In milliseconds
 ENV GRID_NEW_SESSION_WAIT_TIMEOUT -1
 ENV GRID_JETTY_MAX_THREADS -1
+# In milliseconds
 ENV GRID_NODE_POLLING  5000
+# In milliseconds
 ENV GRID_CLEAN_UP_CYCLE 5000
-ENV GRID_TIMEOUT 30000
+# In seconds
+ENV GRID_TIMEOUT 30
+# In seconds
 ENV GRID_BROWSER_TIMEOUT 0
 ENV GRID_MAX_SESSION 5
+# In milliseconds
 ENV GRID_UNREGISTER_IF_STILL_DOWN_AFTER 30000
 
 COPY generate_config /opt/selenium/generate_config
diff --git a/Hub/README.md b/Hub/README.md
index 74b959511f..ff79a2f4cb 100644
--- a/Hub/README.md
+++ b/Hub/README.md
@@ -16,7 +16,7 @@ Note: You can optionally override default configuration settings using environme
 See the [Hub's Dockerfile](Dockerfile) to view the list of variables and their default values.
 
 ```
-$ docker run -d -P --name selenium-hub -e GRID_TIMEOUT=10000 selenium/hub
+$ docker run -d -P --name selenium-hub -e GRID_TIMEOUT=10 selenium/hub
 ```