diff --git a/.travis.yml b/.travis.yml
index 7a99953..dc3f978 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,7 +17,7 @@ matrix:
     - rust: nightly
       env: TEST_COMMAND=test FEATURES=--features="serde"
     - rust: nightly
-      env: TEST_COMMAND=build FEATURES=--no-default-features
+      env: TEST_COMMAND=build FEATURES="--no-default-features --features=u32_backend"
     - rust: nightly
       env: TEST_COMMAND=test FEATURES=--features="nightly"
     - rust: nightly