diff --git a/src/seismic_hazard_forecasting.py b/src/seismic_hazard_forecasting.py
index 6fc5d73..100a651 100644
--- a/src/seismic_hazard_forecasting.py
+++ b/src/seismic_hazard_forecasting.py
@@ -378,8 +378,11 @@ verbose: {verbose}")
 
         # validate m_max against the grond motion model
         models_anthro_limited = ['Lasocki2013', 'Atkinson2015', 'ConvertitoEtAl2012Geysers'] # these models require that m_max<=4.5
-        if m_max > 4.5 and model in models_anthro_limited: 
-            msg = f"Selected ground motion model {model} is only valid up to a maximum magnitude of 4.5. Please try again with a lower maximum magnitude."
+        if m_max > 4.5 and model in models_anthro_limited:
+            if m_file is None: 
+                msg = f"Selected ground motion model {model} is only valid up to a maximum magnitude of 4.5. Please try again with a lower maximum magnitude."
+            else:
+                msg = f"Selected ground motion model {model} is only valid up to a maximum magnitude of 4.5. The magnitude file provided has a range up to {m_max}."
             logger.error(msg)
             raise Exception(msg)