diff --git a/build.sh b/build.sh
index 62142f8e..866b9b16 100755
--- a/build.sh
+++ b/build.sh
@@ -67,8 +67,8 @@ else
         export CC="gcc-11"
         export CXX="g++-11"
     else
-        export CC="clang-11"
-        export CXX="clang++-11"
+        export CC="/usr/bin/clang"
+        export CXX="/usr/bin/clang++"
     fi
 fi
 
diff --git a/setup.sh b/setup.sh
index ef762211..3129bf10 100755
--- a/setup.sh
+++ b/setup.sh
@@ -45,9 +45,9 @@ if [ "$(uname)" == "Darwin" ]; then # osx
 else #linux
     # fix: Package vulkan-utils not found is displayed
     # https://github.com/microsoft/AirSim/issues/4866
-    wget -qO- https://packages.lunarg.com/lunarg-signing-key-pub.asc | sudo tee /etc/apt/trusted.gpg.d/lunarg.asc
-    sudo wget -qO /etc/apt/sources.list.d/lunarg-vulkan-jammy.list http://packages.lunarg.com/vulkan/lunarg-vulkan-jammy.list
-    sudo apt update
+    # wget -qO- https://packages.lunarg.com/lunarg-signing-key-pub.asc | sudo tee /etc/apt/trusted.gpg.d/lunarg.asc
+    # sudo wget -qO /etc/apt/sources.list.d/lunarg-vulkan-jammy.list http://packages.lunarg.com/vulkan/lunarg-vulkan-jammy.list
+    # sudo apt update
     sudo apt-get -y install --no-install-recommends \
         lsb-release \
         rsync \
@@ -64,7 +64,7 @@ else #linux
         wget -O - http://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
         sudo apt-get update
     fi
-    sudo apt-get install -y clang-11 clang++-11 libc++-11-dev libc++abi-11-dev
+    sudo apt-get install -y clang-10 clang++-10 libc++-dev libc++abi-dev
 fi
 
 if ! which cmake; then
@@ -101,8 +101,6 @@ else #linux
     sudo apt-get install -y build-essential unzip
 
     if version_less_than_equal_to "$cmake_ver" "$MIN_CMAKE_VERSION"; then
-        # in ubuntu 18 docker CI, avoid building cmake from scratch to save time
-        # ref: https://apt.kitware.com/
         if [ "$(lsb_release -rs)" == "18.04" ]; then
             sudo apt-get -y install \
                 apt-transport-https \
@@ -130,7 +128,6 @@ else #linux
                 popd
             fi
         fi
-    
     else
         echo "Already have good version of cmake: $cmake_ver"
     fi