diff --git a/src/pmotools/utils/small_utils.py b/src/pmotools/utils/small_utils.py
index bfaaf3e..5701017 100644
--- a/src/pmotools/utils/small_utils.py
+++ b/src/pmotools/utils/small_utils.py
@@ -284,7 +284,7 @@ def outputfile_check(output_file: str, overwrite: bool = False):
             raise Exception(
                 "Output file "
                 + output_file
-                + " already exists, use --overwrite to overwrite it"
+                + " already exists, use overwrite=T (or --overwrite if running from command line interface) to overwrite it"
             )
 
     @staticmethod