diff --git a/setup.py b/setup.py
index 6085f2d..04c2abf 100644
--- a/setup.py
+++ b/setup.py
@@ -57,7 +57,7 @@ extras_require = {
 
 # Add all optional dependencies to testing requirements.
 test_all = []
-for name, requirements in extras_require.items():
+for name, requirements in sorted(extras_require.items()):
     test_all += requirements
 extras_require['test_all'] = test_all