diff --git a/scripts/dev/ci/travis_run.sh b/scripts/dev/ci/travis_run.sh
index 55ca7c11e..a287e844e 100644
--- a/scripts/dev/ci/travis_run.sh
+++ b/scripts/dev/ci/travis_run.sh
@@ -28,5 +28,9 @@ else
     args=()
     [[ $TRAVIS_OS_NAME == osx ]] && args=('--qute-bdd-webengine' '--no-xvfb' 'tests/unit')
 
+    # WORKAROUND for unknown crash inside swrast_dri.so
+    # See https://github.com/qutebrowser/qutebrowser/pull/4218#issuecomment-421931770
+    [[ $TESTENV == py36-pyqt59 ]] && export QT_QUICK_BACKEND=software
+
     tox -e "$TESTENV" -- "${args[@]}"
 fi
diff --git a/tox.ini b/tox.ini
index 02f3ae729..37451918c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,7 @@ setenv =
     pyqt{,56,571,59,510,511}: LINK_PYQT_SKIP=true
     pyqt{,56,571,59,510,511}: QUTE_BDD_WEBENGINE=true
     cov: PYTEST_ADDOPTS=--cov --cov-report xml --cov-report=html --cov-report=
-passenv = PYTHON DISPLAY XAUTHORITY HOME USERNAME USER CI TRAVIS XDG_* QUTE_* DOCKER
+passenv = PYTHON DISPLAY XAUTHORITY HOME USERNAME USER CI TRAVIS XDG_* QUTE_* DOCKER QT_QUICK_BACKEND
 basepython =
     py35: {env:PYTHON:python3.5}
     py36: {env:PYTHON:python3.6}