diff --git a/litellm/types/llms/openai.py b/litellm/types/llms/openai.py
index 24b18cc488a..c0aae9bc2de 100644
--- a/litellm/types/llms/openai.py
+++ b/litellm/types/llms/openai.py
@@ -794,17 +794,19 @@ ValidUserMessageContentTypes = [
     "file",
 ]  # used for validating user messages. Prevent users from accidentally sending anthropic messages.
 
-# Assistant message content types (text, thinking, redacted_thinking)
+# Assistant message content types (text, thinking, redacted_thinking, image_url)
 ValidAssistantMessageContentTypesLiteral = Literal[
     "text",
     "thinking",
     "redacted_thinking",
+    "image_url",
 ]
 
 ValidAssistantMessageContentTypes = [
     "text",
     "thinking",
     "redacted_thinking",
+    "image_url",
 ]
 
 # Combined valid content types for chat completion messages