diff --git a/docker/debian/Dockerfile b/docker/debian/Dockerfile
index e2158d0..9806d46 100644
--- a/docker/debian/Dockerfile
+++ b/docker/debian/Dockerfile
@@ -267,6 +267,14 @@ apt-get install -t llvm-toolchain-${DEBIAN_VERSION}-${CLANG_VERSION} -y --no-ins
   clang-${CLANG_VERSION} \
   libclang-rt-${CLANG_VERSION}-dev \
   llvm-${CLANG_VERSION}
+if [[ "${CLANG_VERSION}" -eq 21 ]]; then
+  apt-get install -y --no-install-recommends --allow-unauthenticated \
+    clang-tidy-${CLANG_VERSION}
+  update-alternatives \
+    --install /usr/bin/clang-tidy clang-tidy /usr/bin/clang-tidy-${CLANG_VERSION} 100
+  update-alternatives \
+    --install /usr/bin/run-clang-tidy run-clang-tidy /usr/bin/run-clang-tidy-${CLANG_VERSION} 100
+fi
 apt-get clean
 rm -rf /var/lib/apt/lists/*
 update-alternatives \
diff --git a/docker/ubuntu/Dockerfile b/docker/ubuntu/Dockerfile
index b668a6f..d15ffb3 100644
--- a/docker/ubuntu/Dockerfile
+++ b/docker/ubuntu/Dockerfile
@@ -228,23 +228,14 @@ printf "%s\n" \
   "Acquire::AllowWeakRepositories \"true\";" \
   | tee /etc/apt/apt.conf.d/99llvm-allow-weak
 
-if [[ "${CLANG_VERSION}" -eq 21 ]]; then
+# Add LLVM repository for versions above 20 because it is not available in the default repo
+if [[ "${CLANG_VERSION}" -gt 20 ]]; then
   apt-get update
-    # Add LLVM repository for versions above 20 because it is not available in the default repo
   apt-get install -y --no-install-recommends lsb-release software-properties-common gnupg
   wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add -
   DISTRO_CODENAME=$(lsb_release -cs)
   echo "deb http://apt.llvm.org/${DISTRO_CODENAME}/ llvm-toolchain-${DISTRO_CODENAME}-${CLANG_VERSION} main" \
     | tee /etc/apt/sources.list.d/llvm.list
-  apt-get update
-  apt-get install -y --no-install-recommends --allow-unauthenticated \
-    clang-tidy-${CLANG_VERSION}
-  update-alternatives \
-    --install /usr/bin/clang-tidy clang-tidy /usr/bin/clang-tidy-${CLANG_VERSION} 100
-  update-alternatives \
-    --install /usr/bin/run-clang-tidy run-clang-tidy /usr/bin/run-clang-tidy-${CLANG_VERSION} 100
-  apt-get clean
-  rm -rf /var/lib/apt/lists/*
 fi
 
 apt-get update