diff --git a/contrib/teamcity/setup-debian-buster.sh b/contrib/teamcity/setup-debian-buster.sh
--- a/contrib/teamcity/setup-debian-buster.sh
+++ b/contrib/teamcity/setup-debian-buster.sh
@@ -68,10 +68,10 @@
 apt-get update
 DEBIAN_FRONTEND=noninteractive apt-get install -y $(join_by ' ' "${PACKAGES[@]}")
 
-TEAMCITY_DIR=$(dirname "$0")
+SCRIPT_DIR=$(dirname "$0")
 
 # Add the AdoptOpenJDK repo
-apt-key add "${TEAMCITY_DIR}"/adoptopenjdk.pub
+apt-key add "${SCRIPT_DIR}"/adoptopenjdk.pub
 add-apt-repository --yes https://adoptopenjdk.jfrog.io/adoptopenjdk/deb/
 apt-get update
 DEBIAN_FRONTEND=noninteractive apt-get install -y adoptopenjdk-8-hotspot
@@ -80,8 +80,9 @@
 echo 'JAVA_HOME="/usr/lib/jvm/default-java"' >> /etc/environment
 
 # Install llvm-8
-apt-key add "${TEAMCITY_DIR}"/llvm.pub
-add-apt-repository "deb http://apt.llvm.org/buster/   llvm-toolchain-buster-8  main"
+apt-key add "${SCRIPT_DIR}"/llvm.pub
+APT_REPO="deb http://apt.llvm.org/buster/   llvm-toolchain-buster-8  main"
+add-apt-repository "${APT_REPO}"
 apt-get update
 
 LLVM_PACKAGES=(
@@ -90,7 +91,17 @@
   clang-tidy-8
   clang-tools-8
 )
-DEBIAN_FRONTEND=noninteractive apt-get install -y $(join_by ' ' "${LLVM_PACKAGES[@]}")
+DEBIAN_FRONTEND=noninteractive apt-get install -y $(join_by ' ' "${LLVM_PACKAGES[@]}") || {
+  # Cleanup any LLVM packages that may have installed successfully
+  apt-get autoremove $(join_by ' ' "${LLVM_PACKAGES[@]}")
+  add-apt-repository --remove "${APT_REPO}"
+
+  # Fallback on buster-backports if packages from LLVM are unavailable
+  add-apt-repository "deb http://deb.debian.org/debian buster-backports main"
+  apt-get update
+  DEBIAN_FRONTEND=noninteractive apt-get -t buster-backports install -y $(join_by ' ' "${LLVM_PACKAGES[@]}")
+}
+
 update-alternatives --install /usr/bin/clang clang "$(command -v clang-8)" 100
 update-alternatives --install /usr/bin/clang++ clang++ "$(command -v clang++-8)" 100