diff --git a/pySim/filesystem.py b/pySim/filesystem.py
index f6dddb6..0494df7 100644
--- a/pySim/filesystem.py
+++ b/pySim/filesystem.py
@@ -713,7 +713,7 @@
         return self.name
 
     def add_application(self, app):
-        self.applications.add(app)
+        self.applications.append(app)
 
     def interpret_sw(self, sw):
         """Interpret a given status word within the profile.  Returns tuple of