diff --git a/.gitlab-ci/debian-install.sh b/.gitlab-ci/debian-install.sh
index e77ae132772..5c947b0d042 100644
--- a/.gitlab-ci/debian-install.sh
+++ b/.gitlab-ci/debian-install.sh
@@ -20,6 +20,15 @@ echo 'deb https://deb.debian.org/debian buster-backports main' >/etc/apt/sources
 
 apt-get update
 
+# Use newer packages from backports by default
+cat >/etc/apt/preferences <<EOF
+Package: *
+Pin: release a=buster-backports
+Pin-Priority: 500
+EOF
+
+apt-get dist-upgrade -y
+
 apt-get install -y --no-remove \
       llvm-6.0-dev \
       libclang-6.0-dev \
diff --git a/.gitlab-ci/debian-stretch-install.sh b/.gitlab-ci/debian-stretch-install.sh
index b9cfa4000b6..906274527b9 100644
--- a/.gitlab-ci/debian-stretch-install.sh
+++ b/.gitlab-ci/debian-stretch-install.sh
@@ -14,6 +14,15 @@ echo 'deb https://deb.debian.org/debian stretch-backports main' >/etc/apt/source
 
 apt-get update
 
+# Use newer packages from backports by default
+cat >/etc/apt/preferences <<EOF
+Package: *
+Pin: release a=stretch-backports
+Pin-Priority: 500
+EOF
+
+apt-get dist-upgrade -y
+
 apt-get install -y --no-remove \
       llvm-3.9-dev \
       libclang-3.9-dev \