diff --git a/.travis.yml b/.travis.yml
index fe7fcee141..43c09617c6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@
 # can't be any leading "-"s - All newlines will be removed, so use ";"s
 
 os: linux
+arch: amd64
 dist: xenial
 language: python
 cache: pip
@@ -16,9 +17,9 @@ env:
         - INSTALL_TYPE="setup"
         - CHECK_TYPE="test"
         - EXTRA_WHEELS="https://3f23b170c54c2533c070-1c8a9b3114517dc5fe17b7c3f8c63a43.ssl.cf2.rackcdn.com"
-        - PRE_WHEELS="https://7933911d6844c6c53a7d-47bd50c35cd79bd838daf386af554a83.ssl.cf2.rackcdn.com"
+        - NIGHTLY_WHEELS="https://pypi.anaconda.org/scipy-wheels-nightly/simple"
         - EXTRA_PIP_FLAGS="--find-links=$EXTRA_WHEELS"
-        - PRE_PIP_FLAGS="--pre $EXTRA_PIP_FLAGS --find-links $PRE_WHEELS"
+        - PRE_PIP_FLAGS="--pre $EXTRA_PIP_FLAGS --extra-index-url $NIGHTLY_WHEELS"
 
 python:
     - 3.7
@@ -26,6 +27,11 @@ python:
 
 jobs:
   include:
+    - arch: arm64
+      python: 3.6
+      env:
+        - DEPENDS="numpy"
+        - EXTRA_PIP_FLAGS="$PRE_PIP_FLAGS"
     # Basic dependencies only
     - python: 3.6
       env:
diff --git a/nibabel/tests/test_volumeutils.py b/nibabel/tests/test_volumeutils.py
index 823350a3cd..f37b3b17ca 100644
--- a/nibabel/tests/test_volumeutils.py
+++ b/nibabel/tests/test_volumeutils.py
@@ -678,7 +678,7 @@ def test_a2f_nan2zero_range():
         with pytest.raises(ValueError):
             write_return(arr_no_nan, fobj, np.int8, intercept=129)
         # OK with nan2zero false, but we get whatever nan casts to
-        nan_cast = np.array(np.nan).astype(np.int8)
+        nan_cast = np.array(np.nan, dtype=dt).astype(np.int8)
         back_arr = write_return(arr, fobj, np.int8, intercept=129, nan2zero=False)
         assert_array_equal([-128, -128, -128, nan_cast], back_arr)
         # divslope