diff --git a/game/missiongenerator/missiongenerator.py b/game/missiongenerator/missiongenerator.py
index 0b9ad36a..bcf8c607 100644
--- a/game/missiongenerator/missiongenerator.py
+++ b/game/missiongenerator/missiongenerator.py
@@ -159,8 +159,8 @@ class MissionGenerator:
         self.initialize_tacan_registry(unique_map_frequencies)
         self.initialize_radio_registry(unique_map_frequencies)
         # Allocate UHF/VHF Guard Freq first!
-        self.radio_registry.reserve(MHz(243))
-        self.radio_registry.reserve(MHz(121, 500))
+        unique_map_frequencies.add(MHz(243))
+        unique_map_frequencies.add(MHz(121, 500))
         for frequency in unique_map_frequencies:
             self.radio_registry.reserve(frequency)