diff --git a/qsomap.py b/qsomap.py
index a5461d9..5226fb9 100755
--- a/qsomap.py
+++ b/qsomap.py
@@ -186,6 +186,10 @@ def qso_data_from_adif(adif_stream):
             continue
 
         grid = qso['GRIDSQUARE']
+
+        if not grid:
+            continue # locator is empty
+
         lat, lon = maidenhead.to_location(grid, center=True)
         call = qso['CALL']