diff --git a/salamanca/data.py b/salamanca/data.py
index 53b9f80..7b8d89a 100644
--- a/salamanca/data.py
+++ b/salamanca/data.py
@@ -157,6 +157,9 @@ def query(self, indicator, tries=5, use_cache=True, overwrite=False, **kwargs):
             df['date'] = df['date'].astype(int)
         except:
             pass
+        # remove NaN countries
+        # TODO: why are there NaNs?
+        df = df.dropna(subset=['country'])
 
         # write to disc if we're caching
         if use_cache and (not exists or overwrite):