sysconfig.get_scheme_names now returns a sorted tuple
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index 1d35082..0c13bba 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -343,7 +343,9 @@
 
 def get_scheme_names():
     """Returns a tuple containing the schemes names."""
-    return _INSTALL_SCHEMES.keys()
+    schemes = _INSTALL_SCHEMES.keys()
+    schemes.sort()
+    return tuple(schemes)
 
 def get_path_names():
     """Returns a tuple containing the paths names."""