diff --git a/.travis.yml b/.travis.yml
index 55d1f13c54a..f276c3ba342 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -167,7 +167,7 @@ install:
   - pip install --upgrade pip
   - pip install --upgrade six
   - pip install --upgrade setuptools
-  - pip install --upgrade codecov
+  - pip install --upgrade codecov coverage==4.5.4
   - pip install --upgrade flake8
   - pip install --upgrade pep8-naming
   - if [[ "$TEST_SUITE" == "doc" ]]; then
diff --git a/share/spack/qa/run-unit-tests b/share/spack/qa/run-unit-tests
index 4403d53a766..11f3ac1fcb5 100755
--- a/share/spack/qa/run-unit-tests
+++ b/share/spack/qa/run-unit-tests
@@ -46,7 +46,7 @@ extra_args=""
 if [[ -n "$@" ]]; then
     extra_args="-k $@"
 fi
-${coverage_run} bin/spack test --verbose "$extra_args"
+${coverage_run} bin/spack test -x --verbose "$extra_args"
 
 #-----------------------------------------------------------
 # Run tests for setup-env.sh