diff --git a/.travis.yml b/.travis.yml
index 3730670..c02af70 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,6 +15,7 @@ matrix:
     - rust: stable
       env:
       - FEATURES='array-sizes-33-128 array-sizes-129-255'
+      - ARRAYVECTEST_ENSURE_MAYBEUNINIT=1
     - rust: beta
     - rust: nightly
       env:
@@ -23,12 +24,12 @@ matrix:
     - rust: nightly
       env:
       - NODROP_FEATURES='use_needs_drop'
-      - ARRAYVECTEST_ENSURE_UNION=1
+      - ARRAYVECTEST_ENSURE_MAYBEUNINIT=1
     - rust: nightly
       env:
       - FEATURES='serde use_union'
       - NODROP_FEATURES='use_union'
-      - ARRAYVECTEST_ENSURE_UNION=1
+      - ARRAYVECTEST_ENSURE_MAYBEUNINIT=1
 branches:
   only:
     - master
diff --git a/tests/tests.rs b/tests/tests.rs
index 0e69467..b8dbadb 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -510,10 +510,8 @@ fn test_sizes_129_255() {
 
 
 #[test]
-fn test_nightly_uses_maybe_uninit() {
-    if option_env!("ARRAYVECTEST_ENSURE_UNION").map(|s| !s.is_empty()).unwrap_or(false) {
-        assert!(cfg!(has_manually_drop_in_union));
-        type ByteArray = ArrayVec<[u8; 4]>;
-        assert!(mem::size_of::<ByteArray>() == 5);
+fn test_newish_stable_uses_maybe_uninit() {
+    if option_env!("ARRAYVECTEST_ENSURE_MAYBEUNINIT").map(|s| !s.is_empty()).unwrap_or(false) {
+        assert!(cfg!(has_stable_maybe_uninit));
     }
 }