diff --git a/Dockerfile b/Dockerfile
index b508634..54abd96 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,8 +1,8 @@
-ARG RUNTIME_VERSION="3.11"
-ARG DISTRO_VERSION="3.19"
+ARG RUNTIME_VERSION="3.12"
+ARG DISTRO_VERSION="3.20"
 
 FROM python:${RUNTIME_VERSION}-alpine${DISTRO_VERSION} AS builder
-ARG RUNTIME_VERSION="3.11"
+ARG RUNTIME_VERSION="3.12"
 
 RUN apk add --no-cache \
     autoconf \
diff --git a/cloudbender/cli.py b/cloudbender/cli.py
index 730b3a2..68401ec 100644
--- a/cloudbender/cli.py
+++ b/cloudbender/cli.py
@@ -447,10 +447,10 @@ def _provision(cb, stacks):
             # Pulumi is still not thread safe
             if _anyPulumi(step):
                 _threads = 1
-            else
+            else:
                 _threads = len(step)
 
-            with ThreadPoolExecutor(max_workers=_threads)) as group:
+            with ThreadPoolExecutor(max_workers=_threads) as group:
                 futures = []
                 for stack in step:
                     if stack.mode != "pulumi":
diff --git a/cloudbender/stack.py b/cloudbender/stack.py
index b514a21..966de34 100644
--- a/cloudbender/stack.py
+++ b/cloudbender/stack.py
@@ -1066,7 +1066,7 @@ class Stack(object):
             if '.' in key:
                 try:
                     (root, leaf) = key.split('.')
-                except ValueError as e:
+                except ValueError:
                     raise ParameterIllegalValue(
                       "Currently only one level hierachies within parameters are supported!"
                     )