diff --git a/Dockerfile b/Dockerfile
index 01368771..4c94b704 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,7 +5,7 @@ ENV GOOGLEAPIS_HASH 47bd0c2ba33c28dd624a65dad382e02bb61d1618
 ENV GAPIC_GENERATOR_HASH 525492e16fda0d3f4979d07ac419619311fc89f6
 # Define version number below. The ARTMAN_VERSION line is parsed by
 # .circleci/config.yml and setup.py, please keep the format.
-ENV ARTMAN_VERSION 0.39.0
+ENV ARTMAN_VERSION 0.40.0
 
 ENV DEBIAN_FRONTEND noninteractive