diff --git a/Dockerfile b/Dockerfile
index 8a09a0b..78a151d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -17,7 +17,7 @@
 # Start the container with an external volume mounted at /home/data:
 # `docker run -dit --name mesh2hrtf -v '/local/folder:/home/data' ubuntu:mesh2hrtf /bin/bash`
 
-FROM ubuntu:22.04
+FROM ubuntu:24.04
 
 # All commands are run from this path
 WORKDIR /home
@@ -29,7 +29,8 @@ WORKDIR /home
 # install required dependencies (remove specific versions if desired)
 RUN apt-get update
 RUN DEBIAN_FRONTEND=noninteractive apt-get upgrade -y
-RUN DEBIAN_FRONTEND=noninteractive apt-get install -y cmake \
+RUN DEBIAN_FRONTEND=noninteractive apt-get install -y \
+                   cmake \
                    make \
                    build-essential\
                    libx11-dev \
@@ -41,7 +42,13 @@ RUN DEBIAN_FRONTEND=noninteractive apt-get install -y cmake \
                    libglu1-mesa-dev \
                    libeigen3-dev \
                    python3 \
-                   python3-pip
+                   python3-pip \
+                   python3-venv
+
+# create and prepend it to the path
+# (all python commands will use venv after this)
+RUN python3 -m venv venv
+ENV PATH="/home/venv/bin:$PATH"
 
 # copy Mesh2HRTF git repo to docker container
 COPY . /home/Mesh2HRTF
@@ -49,8 +56,10 @@ COPY . /home/Mesh2HRTF
 # install Mesh2HRTF Python API
 RUN pip install -e /home/Mesh2HRTF
 
-# build NumCalc
-RUN cd /home/Mesh2HRTF/mesh2hrtf/NumCalc/src && make
+# build NumCalc and run make clean if any *.o files exist
+RUN cd /home/Mesh2HRTF/mesh2hrtf/NumCalc/src && \
+    if ls *.o 1> /dev/null 2>&1; then make clean; fi && \
+    make
 
 # add symbolic linc for NumCalc
 RUN ln -s /home/Mesh2HRTF/mesh2hrtf/NumCalc/bin/NumCalc /usr/local/bin
diff --git a/HISTORY.rst b/HISTORY.rst
index 9b1d4fe..d1d700b 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -1,6 +1,10 @@
 History
 =======
 
+v1.2.1 (11 September 2024)
+--------------------------
+* Update dockerfile: update to latest long time support Ubuntu version, create a Python virtual environment because Python 3.12 does not allow `pip install` outside an environment anymore.
+
 v1.2.0 (1 July 2024)
 --------------------
 * `hrtf_mesh_grading` from the folder mesh2hrtf/Mesh2Input/Meshes/GradingHybrid can now also do purely distance based mesh grading
diff --git a/VERSION b/VERSION
index 26aaba0..6085e94 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.2.0
+1.2.1
diff --git a/mesh2hrtf/Mesh2Input/mesh2input.py b/mesh2hrtf/Mesh2Input/mesh2input.py
index 217d24b..98a1d39 100644
--- a/mesh2hrtf/Mesh2Input/mesh2input.py
+++ b/mesh2hrtf/Mesh2Input/mesh2input.py
@@ -15,7 +15,7 @@
 bl_info = {
     "name": "Mesh2HRTF export add-on",
     "author": "The Mesh2HRTF developers",
-    "version": (1, 2, 0),
+    "version": (1, 2, 1),
     "blender": (2, 80, 0),
     "location": "File > Export",
     "description": "Export Blender scene as Mesh2HRTF project",
diff --git a/mesh2hrtf/__init__.py b/mesh2hrtf/__init__.py
index 2bed9b6..e01ea14 100644
--- a/mesh2hrtf/__init__.py
+++ b/mesh2hrtf/__init__.py
@@ -20,7 +20,7 @@
     write_evaluation_grid
 from .Mesh2Input.Materials.write_material import write_material
 
-__version__ = '1.2.0'
+__version__ = '1.2.1'
 
 __all__ = [
     'output2hrtf',