diff --git a/SAS/TMSS/src/tmss/tmssapp/conversions.py b/SAS/TMSS/src/tmss/tmssapp/conversions.py
index 2c1e27da04d690bbfc96e07e7e3c14776103f2e6..13b5040ccb6da9a2ff92cfe044924767b7205bc8 100644
--- a/SAS/TMSS/src/tmss/tmssapp/conversions.py
+++ b/SAS/TMSS/src/tmss/tmssapp/conversions.py
@@ -25,7 +25,7 @@ def create_astroplan_observer_for_station(station: str) -> Observer:
 SUN_SET_RISE_ANGLE_TO_HORIZON = Angle(10, unit=astropy.units.deg)
 SUN_SET_RISE_PRECISION = 15  # n_grid_points; higher is more precise but very costly; astropy defaults to 150, 15 seems to cause errors of typically one minute
 
-@lru_cache(maxsize=256, typed=False)  # does not like lists, so use sets to allow caching
+@lru_cache(maxsize=256, typed=False)  # does not like lists, so use tuples to allow caching
 def timestamps_and_stations_to_sun_rise_and_set(timestamps: tuple, stations: tuple, angle_to_horizon: Angle=SUN_SET_RISE_ANGLE_TO_HORIZON) -> dict:
     """
     compute sunrise, sunset, day and night of the given stations at the given timestamps
@@ -63,7 +63,8 @@ def timestamps_and_stations_to_sun_rise_and_set(timestamps: tuple, stations: tup
     return return_dict
 
 
-@lru_cache(maxsize=256, typed=False)  # does not like lists, so use sets to allow caching
+# Depending on usage patterns, we should consider refactoring this a little so that we cache on a function with a single timestamp as input. Requests with similar (but not identical) timestamps or bodies currently make no use of cached results for the subset computed in previous requests.
+@lru_cache(maxsize=256, typed=False)  # does not like lists, so use tuples to allow caching
 def coordinates_and_timestamps_to_separation_from_bodies(angle1: float, angle2: float, direction_type: str, timestamps: tuple, bodies: tuple) -> dict:
     """
     compute angular distances of the given sky coordinates from the given solar system bodies at the given timestamps (seen from LOFAR core)