diff --git a/README.md b/README.md
index 59e03699..d74ba55a 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@ Just please make sure to pass all the necessary environment variables through:
 
 ```
 [testenv]
-passenv = TOXENV CI TRAVIS TRAVIS_*
+passenv = TOXENV CI TRAVIS TRAVIS_* CODECOV_*
 deps = codecov>=1.4.0
 commands = codecov -e TOXENV
 ```