diff --git a/finance.py b/finance.py
index e471fe6..4491ad2 100755
--- a/finance.py
+++ b/finance.py
@@ -164,12 +164,13 @@ def update_table(selected_dropdown_value):
 def change_time_period(selectedData):
     global from_time
     global to_time
-    if selectedData.get('autosize'):
-        from_time = selected_stock_in_table_df.index.min()
-        to_time = selected_stock_in_table_df.index.max()
-    else:
-        from_time = selectedData["xaxis.range[0]"]
-        to_time = selectedData["xaxis.range[1]"]
+    if selectedData is not None:
+        if selectedData.get('autosize'):
+            from_time = selected_stock_in_table_df.index.min()
+            to_time = selected_stock_in_table_df.index.max()
+        else:
+            from_time = selectedData["xaxis.range[0]"]
+            to_time = selectedData["xaxis.range[1]"]
     average_gauge = make_gauge('średnia', 0, 290, 400)
     volatility_gauge = make_gauge('wolatylność', 0, 133, 400)
     return average_gauge, volatility_gauge