diff --git a/.travis.yml b/.travis.yml
index 18e48ce..c3f0a73 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -26,13 +26,11 @@ script:
 
 after_success: |
   if [[ "$TRAVIS_RUST_VERSION" == stable ]]; then
-    which cargo-install-update || cargo install cargo-update
-    cargo install-update --all
-
-    # Uncomment the following line for coveralls.io
-    # cargo tarpaulin --ciserver travis-ci --coveralls $TRAVIS_JOB_ID
-
-    # Uncomment the following two lines create and upload a report for codecov.io
+        which cargo-install-update || cargo install cargo-update
+        cargo install-update --all
+  fi
+  # this does require a -Z flag for Doctests, which is unstable!
+  if [[ "$TRAVIS_RUST_VERSION" == nightly ]]; then
     cargo tarpaulin --out Xml --run-types Tests Doctests
     bash <(curl -s https://codecov.io/bash)
   fi