diff --git a/analysisstore/server/astore.py b/analysisstore/server/astore.py
index ea984e0..9bf17f7 100644
--- a/analysisstore/server/astore.py
+++ b/analysisstore/server/astore.py
@@ -20,6 +20,7 @@ def __init__(self, config, testing=False):
         if not testing:
             try:
                 self.client = MongoClient(config["uri"])
+                # Proactively check that connection to server is working.
                 self.client.server_info()
             except (pymongo.errors.ConnectionFailure, pymongo.errors.ServerSelectionTimeoutError):
                 raise AnalysisstoreException("Unable to connect to MongoDB server...")