diff --git a/Dockerfile b/Dockerfile
index ff34993..45eb9ba 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,7 @@ COPY . /git/
 RUN find . -type d -name .git -exec git describe --always --dirty > /git-version.txt \;
 
 
-FROM python:3.13
+FROM python:3.12
 
 EXPOSE 8080
 
diff --git a/requirements.txt b/requirements.txt
index 39e0926..2982f57 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 tornado==6.4.1
-isodate==0.7.2
+isodate==0.6.1
 pytest==8.3.3
 schwifty==2024.9.0
 Cerberus==1.3.5