diff --git a/scripts/ct/run.sh b/scripts/ct/run.sh
index edfaf6a9e..5a2cce036 100755
--- a/scripts/ct/run.sh
+++ b/scripts/ct/run.sh
@@ -83,7 +83,7 @@ if [ -f "$DOCKER_CT_ENVS_FILE" ]; then
     # shellcheck disable=SC2002
     CT_DEPS="$(cat "$DOCKER_CT_ENVS_FILE" | xargs)"
 fi
-CT_DEPS="${ERLANG_CONTAINER} ${CT_DEPS}"
+CT_DEPS="${ERLANG_CONTAINER} ${CT_DEPS:-}"
 
 FILES=( )