diff --git a/cf/main.py b/cf/main.py
index 7bd93bd..9ff2a0d 100644
--- a/cf/main.py
+++ b/cf/main.py
@@ -125,19 +125,19 @@ def get_temp_table_query(self):
                   SELECT          
                         CONCAT(
                               stream_id, 
-                              ".",
+                              "_",
                               IFNULL(user_pseudo_id, ""), 
-                              ".",
+                              "_",
                               event_name,
-                              ".",
+                              "_",
                               event_timestamp, 
-                              ".",
+                              "_",
                               IFNULL(CAST(batch_event_index AS STRING),  ""),
-                              ".",
+                              "_",
                               IFNULL(CAST(batch_page_id AS STRING),  ""),
-                              ".",
+                              "_",
                               IFNULL(CAST(batch_ordering_id AS STRING), ""),
-                              ".",
+                              "_",
                             
                               ROW_NUMBER() OVER (PARTITION BY CONCAT(
                                                               stream_id, 
@@ -162,8 +162,8 @@ def get_events_query_select_statement(self):
         qry = f"""SELECT
                     PARSE_DATE('%Y%m%d', event_date) AS event_date,
                     event_id,
-                    CONCAT(user_pseudo_id, ".",(SELECT value.int_value from UNNEST(event_params) WHERE key = 'ga_session_id')) as session_id,
-                    CONCAT(user_pseudo_id, ".",(SELECT value.int_value from UNNEST(event_params) WHERE key = 'ga_session_number')) as session_id_1,
+                    CONCAT(user_pseudo_id, "_",(SELECT value.int_value from UNNEST(event_params) WHERE key = 'ga_session_id')) as session_id,
+                    CONCAT(user_pseudo_id, "_",(SELECT value.int_value from UNNEST(event_params) WHERE key = 'ga_session_number')) as session_id_1,
                 
                     event_timestamp AS event_timestamp,
                     event_name AS event_name,
diff --git a/tests/rsc/sample_desired_queries.py b/tests/rsc/sample_desired_queries.py
index 049ea65..3a595f1 100644
--- a/tests/rsc/sample_desired_queries.py
+++ b/tests/rsc/sample_desired_queries.py
@@ -5,8 +5,8 @@
     PARSE_DATE('%%Y%%m%%d', event_date) AS event_date,
     event_id,
     
-    CONCAT(user_pseudo_id, ".",(SELECT value.int_value from UNNEST(event_params) WHERE key = 'ga_session_id')) as session_id,
-    CONCAT(user_pseudo_id, ".",(SELECT value.int_value from UNNEST(event_params) WHERE key = 'ga_session_number')) as session_id_1,
+    CONCAT(user_pseudo_id, "_",(SELECT value.int_value from UNNEST(event_params) WHERE key = 'ga_session_id')) as session_id,
+    CONCAT(user_pseudo_id, "_",(SELECT value.int_value from UNNEST(event_params) WHERE key = 'ga_session_number')) as session_id_1,
 
     event_timestamp AS event_timestamp,
     event_name AS event_name,