diff --git a/run_tests.sh b/run_tests.sh
index 969e3db..e8f6f3a 100755
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -35,9 +35,12 @@ source /etc/os-release || source /usr/lib/os-release
 install_pkg_deps() {
     pkg_deps="git"
 
+    # Prefer dnf over yum for CentOS.
+    which dnf &>/dev/null && RHT_PKG_MGR='dnf' || RHT_PKG_MGR='yum'
+
     case ${ID,,} in
         *suse*) pkg_mgr_cmd="zypper -n in" ;;
-        centos|rhel) pkg_mgr_cmd="yum install -y" ;;
+        centos|rhel) pkg_mgr_cmd="${RHT_PKG_MGR} install -y" ;;
         fedora) pkg_mgr_cmd="dnf -y install" ;;
         ubuntu|debian) pkg_mgr_cmd="apt-get install -y" ;;
         *) echo "unsupported distribution: ${ID,,}"; exit 1 ;;