diff --git a/setup.py b/setup.py
index e00d0f86b..0573c2958 100755
--- a/setup.py
+++ b/setup.py
@@ -577,7 +577,7 @@ class picard_patch_version(Command):
     ]
 
     def initialize_options(self):
-        self.platform = 'unknown'
+        self.platform = sys.platform
 
     def finalize_options(self):
         pass