diff --git a/.travis.yml b/.travis.yml
index 6af9239..a5b5c1f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,16 +4,17 @@ rust:
   - nightly
 
 env:
-  - TEST_COMMAND=test EXTRA_FLAGS='' FEATURES=''
-  - TEST_COMMAND=bench EXTRA_FLAGS='' FEATURES=''
-  - TEST_COMMAND=build EXTRA_FLAGS='--no-default-features' FEATURES='nightly'
+  - TEST_COMMAND=test EXTRA_FLAGS='' FEATURES='default'
+  - TEST_COMMAND=bench EXTRA_FLAGS='' FEATURES='default'
+  - TEST_COMMAND=build EXTRA_FLAGS='--no-default-features' FEATURES='u32_backend nightly'
+  - TEST_COMMAND=build EXTRA_FLAGS='--no-default-features' FEATURES='u64_backend nightly'
 
 matrix:
   include:
     - rust: stable
-      env: TEST_COMMAND=test EXTRA_FLAGS='--no-default-features' FEATURES='std'
+      env: TEST_COMMAND=test EXTRA_FLAGS='--no-default-features' FEATURES='std u64_backend'
     - rust: beta
-      env: TEST_COMMAND=test EXTRA_FLAGS='--no-default-features' FEATURES='std'
+      env: TEST_COMMAND=test EXTRA_FLAGS='--no-default-features' FEATURES='std u64_backend'
 
 script:
   - cargo $TEST_COMMAND --features="$FEATURES" $EXTRA_FLAGS