diff --git a/pyanaconda/modules/payloads/payload/flatpak/flatpak_manager.py b/pyanaconda/modules/payloads/payload/flatpak/flatpak_manager.py
index 5e677e0c4b3..17acc413a9a 100644
--- a/pyanaconda/modules/payloads/payload/flatpak/flatpak_manager.py
+++ b/pyanaconda/modules/payloads/payload/flatpak/flatpak_manager.py
@@ -126,7 +126,7 @@ def _get_source(self):
 
         return self._source
 
-    def calculate_size(self, progress: Optional[ProgressReporter]):
+    def calculate_size(self):
         """Calculate the download and install size of the Flatpak content.
 
         :param progress: used to report progress of the operation
diff --git a/pyanaconda/modules/payloads/payload/flatpak/installation.py b/pyanaconda/modules/payloads/payload/flatpak/installation.py
index 97f605414a3..c05702a5cc9 100644
--- a/pyanaconda/modules/payloads/payload/flatpak/installation.py
+++ b/pyanaconda/modules/payloads/payload/flatpak/installation.py
@@ -43,7 +43,7 @@ def name(self):
         return "Calculate needed space for Flatpaks"
 
     def run(self):
-        self._flatpak_manager.calculate_size(self)
+        self._flatpak_manager.calculate_size()
 
 
 class PrepareDownloadLocationTask(Task):
diff --git a/pyanaconda/modules/payloads/payloads.py b/pyanaconda/modules/payloads/payloads.py
index 0106812d1c9..6178e4fb254 100644
--- a/pyanaconda/modules/payloads/payloads.py
+++ b/pyanaconda/modules/payloads/payloads.py
@@ -154,7 +154,7 @@ def calculate_required_space(self):
         if self.active_payload:
             total += self.active_payload.calculate_required_space()
             if self._flatpak_side_payload:
-                self._flatpak_side_payload.set_sources(self.active_payload.get_sources())
+                self._flatpak_side_payload.set_sources(self.active_payload.sources)
                 self._flatpak_side_payload.set_flatpak_refs(self.active_payload.get_flatpak_refs())
                 total += self._flatpak_side_payload.calculate_required_space()