diff --git a/views.py b/views.py
index f1b1b09..b537450 100644
--- a/views.py
+++ b/views.py
@@ -369,7 +369,11 @@ class UpperLimitView(APIView):
         # NEARBY SOURCES CHECK
         # ****************************************************************
 
-        radius_as = map_radius * 2
+        if map_radius == 0:
+            radius_as = 5 * aperture_radius
+        else:
+            radius_as = map_radius * 2
+
         radius_deg = radius_as / 3600
 
         dec_min = max(dec - radius_deg, -90)