diff --git a/share/spack/qa/run-docker-tests b/share/spack/qa/run-docker-tests
index 9030d8169cade645b901adcf68a9a65691cb2ed1..6e7469e178dc18045531340cb51dbda460482fda 100755
--- a/share/spack/qa/run-docker-tests
+++ b/share/spack/qa/run-docker-tests
@@ -32,8 +32,11 @@ ensure_docker_login() {
     return $__login_success
 }
 
+this_dir=$(cd $(dirname $0) && pwd)
+SPACK_BIN="${this_dir}/../../../bin/spack"
+
 # packages.spack.io service
-spack list --format version_json > packages.json
+${SPACK_BIN} list --format version_json > packages.json
 ./share/spack/packages/build-image.sh
 if [ "$TEST_SUITE" '=' "docker" -a \
      "$TRAVIS_EVENT_TYPE" != "pull_request" ] && ensure_docker_login ; then