diff --git a/run_agent.py b/run_agent.py
index bca3dd1e718..331ff2c66ab 100644
--- a/run_agent.py
+++ b/run_agent.py
@@ -1483,7 +1483,15 @@ class AIAgent:
         if 0 <= idx < len(messages):
             msg = messages[idx]
             if isinstance(msg, dict) and msg.get("role") == "user":
-                if override is not None:
+                # Text-only call paths may pass a synthetic API-facing prompt
+                # and a cleaner transcript string separately. Multimodal
+                # turns, however, keep image/audio blocks in the live
+                # messages list that is still used for the API request after
+                # early crash-resilience persistence. Do not replace those
+                # blocks with the text-only persistence override before the
+                # model call is built. The paired timestamp override still
+                # applies — it is metadata, not content.
+                if override is not None and not isinstance(msg.get("content"), list):
                     msg["content"] = override
                 if timestamp is not None:
                     msg["timestamp"] = timestamp
diff --git a/tests/run_agent/test_run_agent.py b/tests/run_agent/test_run_agent.py
index 827bc0ef690..f2787628d4d 100644
--- a/tests/run_agent/test_run_agent.py
+++ b/tests/run_agent/test_run_agent.py
@@ -75,6 +75,33 @@ def agent():
         return a
 
 
+def test_persist_user_message_override_rewrites_text_turns(agent):
+    messages = [{"role": "user", "content": "API-only synthetic prefix\nhello"}]
+    agent._persist_user_message_idx = 0
+    agent._persist_user_message_override = "hello"
+
+    agent._apply_persist_user_message_override(messages)
+
+    assert messages == [{"role": "user", "content": "hello"}]
+
+
+def test_persist_user_message_override_preserves_multimodal_turns(agent):
+    multimodal_content = [
+        {"type": "text", "text": "What color is this?"},
+        {
+            "type": "image_url",
+            "image_url": {"url": "data:image/png;base64,AAAA"},
+        },
+    ]
+    messages = [{"role": "user", "content": multimodal_content}]
+    agent._persist_user_message_idx = 0
+    agent._persist_user_message_override = "What color is this? [Image attachment]"
+
+    agent._apply_persist_user_message_override(messages)
+
+    assert messages == [{"role": "user", "content": multimodal_content}]
+
+
 @pytest.fixture()
 def agent_with_memory_tool():
     """Agent whose valid_tool_names includes 'memory'."""