diff --git a/src/smolagents/monitoring.py b/src/smolagents/monitoring.py
index 93a641e..d7deb44 100644
--- a/src/smolagents/monitoring.py
+++ b/src/smolagents/monitoring.py
@@ -59,7 +59,7 @@ class Monitor:
         """
         step_duration = step_log.duration
         self.step_durations.append(step_duration)
-        console_outputs = f"[Step {len(self.step_durations) - 1}: Duration {step_duration:.2f} seconds"
+        console_outputs = f"[Step {len(self.step_durations)}: Duration {step_duration:.2f} seconds"
 
         if getattr(self.tracked_model, "last_input_token_count", None) is not None:
             self.total_input_token_count += self.tracked_model.last_input_token_count