diff --git a/src/google/adk/evaluation/simulation/per_turn_user_simulator_quality_prompts.py b/src/google/adk/evaluation/simulation/per_turn_user_simulator_quality_prompts.py
index 1862272cf3b..985011fe355 100644
--- a/src/google/adk/evaluation/simulation/per_turn_user_simulator_quality_prompts.py
+++ b/src/google/adk/evaluation/simulation/per_turn_user_simulator_quality_prompts.py
@@ -146,7 +146,7 @@
 
 # Definition of Conversation History
 The Conversation History is the actual dialogue between the User Simulator and the Agent.
-The Conversation History may not be complete, but the exsisting dialogue should adhere to the Conversation Plan.
+The Conversation History may not be complete, but the existing dialogue should adhere to the Conversation Plan.
 The Conversation History may contain instances where the User Simulator troubleshoots an incorrect/inappropriate response from the Agent in order to enforce the Conversation Plan.
 The Conversation History is finished only when the User Simulator outputs `{{ stop_signal }}` in its response. If this token is missing, the conversation between the User Simulator and the Agent has not finished, and more turns can be generated.