diff --git a/common_task.py b/common_task.py
index 8cc21fb..a254c9a 100644
--- a/common_task.py
+++ b/common_task.py
@@ -56,10 +56,12 @@ def do_the_difference(today_file, last_file, column_for_diff, fresh_output, expi
     expired_df = pd.merge(last_file_df, today_df, on=column_for_diff, how='left', indicator=True,  suffixes=('', '_ignored')).query('_merge == "left_only"').drop(['_merge'], axis=1)
     child_df_copy = expired_df.copy()
     if gi =="g":
-        child_df_copy['Job Key'] = 'g_' + child_df_copy['Job Key']
+        child_df_copy['Job Key'] = 'g_' + child_df_copy['Job Key'].astype(str)
+        expired_df['Job key'] = expired_df['Job key'].astype(str)
         expired_df = pd.concat([expired_df, child_df_copy], ignore_index=True)
     else: # jobId
-        child_df_copy['jobId'] = 'i_' + child_df_copy['jobId']
+        child_df_copy['jobId'] = 'i_' + child_df_copy['jobId'].astype(str)
+        expired_df['jobId'] = expired_df['jobId'].astype(str)
         expired_df = pd.concat([expired_df, child_df_copy], ignore_index=True)
 
     expired_df.to_csv(expired_output, index=False)