diff --git a/tools/verify/Dockerfile b/tools/verify/Dockerfile
index 740ab85c..2351ffea 100644
--- a/tools/verify/Dockerfile
+++ b/tools/verify/Dockerfile
@@ -1,6 +1,6 @@
 ARG PYTHON_VERSION
 
-FROM python:${PYTHON_VERSION}
+FROM python:${PYTHON_VERSION}-slim
 
 RUN pip install --upgrade pip
 RUN pip install tox
diff --git a/verify.sh b/verify.sh
index 90bfb2fa..11b44439 100755
--- a/verify.sh
+++ b/verify.sh
@@ -13,6 +13,7 @@ if [ -z "$1" ]; then
     validate 3.6.2
     validate 3.7.2
     validate 3.8.0
+    validate 3.9.0
 else
     echo "Validating only $1..."
     validate "$1"