diff --git a/tf-dev/Dockerfile b/tf-dev/Dockerfile
index f473b18..336df0c 100644
--- a/tf-dev/Dockerfile
+++ b/tf-dev/Dockerfile
@@ -1,6 +1,6 @@
 FROM git.luke-else.co.uk/luke-else/lab:latest
 
-RUN sudo apk add --no-cache ansible py3-requests py3-datetime
+RUN sudo apk add --no-cache ansible py3-requests py3-dateutil
 
 # Download the installer script:
 RUN curl --proto '=https' --tlsv1.2 -fsSL https://get.opentofu.org/install-opentofu.sh -o install-opentofu.sh