diff --git a/tests/python/testing.py b/tests/python/testing.py
index c33782bece9a..54c6a274e647 100644
--- a/tests/python/testing.py
+++ b/tests/python/testing.py
@@ -24,7 +24,7 @@
 
 
 def is_arm():
-    return {'condition': platform.machine().lower().find('arm') != 1,
+    return {'condition': platform.machine().lower().find('arm') != -1,
             'reason': 'Skipping expensive tests on ARM.'}
 
 def no_sklearn():