diff --git a/entrypoint.sh b/entrypoint.sh
index f5b8389..63511b7 100644
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -8,5 +8,20 @@ if ! nvidia-smi > /dev/null 2>&1; then
     echo "WARNING: The NVIDIA Driver was not detected. GPU functionality will not be available."
 fi
 
+# Conditionally force Mesa for software rendering.
+# Commit dd662d8 added __GLX_VENDOR_LIBRARY_NAME=mesa to fix window creation on
+# setups without NVIDIA GLX passthrough (e.g. CPU-only or WSL2 without graphics
+# bindings). However, forcing Mesa breaks native NVIDIA GLX passthrough because
+# Mesa tries to load the nvidia-drm DRI driver, which is not present in the
+# container, leading to Zink/Vulkan swapchain errors.
+# Only set it when NVIDIA GLX libraries are absent and the user hasn't
+# explicitly configured it.
+if [ -z "${__GLX_VENDOR_LIBRARY_NAME+x}" ]; then
+    if ! ldconfig -p 2>/dev/null | grep -q "libGLX_nvidia.so.0"; then
+        export __GLX_VENDOR_LIBRARY_NAME=mesa
+        echo "INFO: NVIDIA GLX libraries not found. Forcing Mesa for software rendering."
+    fi
+fi
+
 # keep container running
 exec "$@"
diff --git a/puffertank.dockerfile b/puffertank.dockerfile
index 7badb7e..e0cc5de 100644
--- a/puffertank.dockerfile
+++ b/puffertank.dockerfile
@@ -66,8 +66,7 @@ RUN echo "export PS1=$''" >> ~/.bashrc \
  && echo "alias diff='diff --color --palette=':ad=36:de=31:ln=33''" >> ~/.bashrc \
  && echo "alias pip='uv pip'" >> ~/.bashrc \
  && echo ". /puffertank/venv/bin/activate" >> ~/.bashrc \
- && echo "cd /puffertank/pufferlib" >> ~/.bashrc \
- && echo "export __GLX_VENDOR_LIBRARY_NAME=mesa" >> ~/.bashrc
+ && echo "cd /puffertank/pufferlib" >> ~/.bashrc
 
 RUN apt-get clean
 CMD ["/bin/bash"]