diff --git a/.travis.yml b/.travis.yml
index e51523c19..85eabc9ed 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,7 +15,7 @@ matrix:
     - python: '2.7'
       env:
         - TOXENV=du13
-        - PYTEST_ADDOPTS = --cov sphinx --cov-append --cov-config setup.cfg
+        - PYTEST_ADDOPTS="--cov ./ --cov-append --cov-config setup.cfg"
     - python: '3.4'
       env: TOXENV=py34
     - python: '3.5'
@@ -23,7 +23,7 @@ matrix:
     - python: '3.6'
       env:
         - TOXENV=py36
-        - PYTEST_ADDOPTS = --cov sphinx --cov-append --cov-config setup.cfg
+        - PYTEST_ADDOPTS="--cov ./ --cov-append --cov-config setup.cfg"
     - python: 'nightly'
       env: TOXENV=py37
     - python: '3.6'
@@ -46,4 +46,4 @@ script:
   - tox -- -v
 
 after_success:
-  - codecov
+  - if [[ -e .coverage ]]; then codecov -e $TOXENV; fi
diff --git a/tox.ini b/tox.ini
index 45bc438b2..b8d6a0e32 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@ envlist = docs,flake8,mypy,coverage,py{27,34,35,36,py},du{11,12,13,14}
 [testenv]
 usedevelop = True
 passenv =
-    https_proxy http_proxy no_proxy PERL PERL5LIB
+    https_proxy http_proxy no_proxy PERL PERL5LIB PYTEST_ADDOPTS
 description =
     py{27,34,35,36,py}: Run unit tests against {envname}.
     du{11,12,13,14}: Run unit tests with the given version of docutils.