diff --git a/code-style-check/Dockerfile b/code-style-check/Dockerfile
index d248c7cdfa9855acbd606036c3a3a7b44b989fb1..d8431f9d469be99c8970785ac889623f36dc896e 100644
--- a/code-style-check/Dockerfile
+++ b/code-style-check/Dockerfile
@@ -1,14 +1,17 @@
 FROM debian:sid
 LABEL maintainer="Ingo Heimbach <i.heimbach@fz-juelich.de>"
 
-ARG CLANG_FORMAT_VERSION="8"
+ARG CLANG_FORMAT_VERSION="9"
 ARG CMAKE_FORMAT_VERSION="0.6.7"
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends "clang-format-${CLANG_FORMAT_VERSION}" file git python3-pip \
                                                python3-setuptools python3-wheel && \
+    update-alternatives --install "/usr/bin/clang-format" \
+                                  "clang-format" \
+                                  "/usr/bin/clang-format-${CLANG_FORMAT_VERSION}" \
+                                  1 && \
     python3 -m pip install "cmake_format==${CMAKE_FORMAT_VERSION}" && \
-    rm -rf /var/lib/apt/lists/* && \
-    ln -s /usr/bin/clang-format-${CLANG_FORMAT_VERSION} /usr/local/bin/clang-format
+    rm -rf /var/lib/apt/lists/*
 
 CMD ["/bin/bash"]