diff --git a/.travis.yml b/.travis.yml
index 7ae9f4952d..f9ee2ab0fe 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -44,6 +44,7 @@ script:
   # run tests with coverage info
   - make -C unix coverage
   - (cd tests && MICROPY_CPYTHON3=python3.4 MICROPY_MICROPYTHON=../unix/micropython_coverage ./run-tests)
+  - (cd tests && MICROPY_CPYTHON3=python3.4 MICROPY_MICROPYTHON=../unix/micropython_coverage ./run-tests -d thread)
   - (cd tests && MICROPY_CPYTHON3=python3.4 MICROPY_MICROPYTHON=../unix/micropython_coverage ./run-tests --emit native)
 
 after_success: