diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index b00992c8f..85228df2b 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -1077,6 +1077,10 @@ class Coder:
             shell_cmd_reminder=shell_cmd_reminder,
             language=language,
         )
+
+        if self.main_model.system_prompt_prefix:
+            prompt = self.main_model.system_prompt_prefix + prompt
+
         return prompt
 
     def format_chat_chunks(self):
diff --git a/aider/models.py b/aider/models.py
index 227204fa7..4f4ed499b 100644
--- a/aider/models.py
+++ b/aider/models.py
@@ -114,6 +114,7 @@ class ModelSettings:
     editor_model_name: Optional[str] = None
     editor_edit_format: Optional[str] = None
     remove_reasoning: Optional[str] = None
+    system_prompt_prefix: Optional[str] = None
 
 
 # Load model settings from package resource
@@ -294,6 +295,7 @@ class Model(ModelSettings):
             self.edit_format = "diff"
             self.use_repo_map = True
             self.use_temperature = False
+            self.system_prompt_prefix = "Formatting re-enabled. "
             return  # <--
 
         if "/o1-mini" in model:
@@ -314,6 +316,7 @@ class Model(ModelSettings):
             self.use_repo_map = True
             self.use_temperature = False
             self.streaming = False
+            self.system_prompt_prefix = "Formatting re-enabled. "
             return  # <--
 
         if "deepseek" in model and "v3" in model:
diff --git a/aider/resources/model-settings.yml b/aider/resources/model-settings.yml
index be681827f..8a314c86a 100644
--- a/aider/resources/model-settings.yml
+++ b/aider/resources/model-settings.yml
@@ -569,6 +569,7 @@
   streaming: false
   editor_model_name: openrouter/openai/gpt-4o
   editor_edit_format: editor-diff
+  system_prompt_prefix: "Formatting re-enabled. "
 
 - name: openai/o1
   edit_format: diff
@@ -578,6 +579,7 @@
   streaming: false
   editor_model_name: openai/gpt-4o
   editor_edit_format: editor-diff
+  system_prompt_prefix: "Formatting re-enabled. "
 
 - name: o1
   edit_format: diff
@@ -587,6 +589,7 @@
   streaming: false
   editor_model_name: gpt-4o
   editor_edit_format: editor-diff
+  system_prompt_prefix: "Formatting re-enabled. "
 
 - name: openrouter/qwen/qwen-2.5-coder-32b-instruct
   edit_format: diff
@@ -634,6 +637,7 @@
   use_temperature: false
   editor_model_name: gpt-4o
   editor_edit_format: editor-diff
+  system_prompt_prefix: "Formatting re-enabled. "
   
 - name: o3-mini
   edit_format: diff
@@ -642,6 +646,7 @@
   use_temperature: false
   editor_model_name: gpt-4o
   editor_edit_format: editor-diff
+  system_prompt_prefix: "Formatting re-enabled. "
 
 - name: openrouter/openai/o3-mini
   edit_format: diff
@@ -650,6 +655,7 @@
   use_temperature: false
   editor_model_name: openrouter/openai/gpt-4o
   editor_edit_format: editor-diff
+  system_prompt_prefix: "Formatting re-enabled. "
 
 - name: azure/o3-mini
   edit_format: diff
@@ -658,5 +664,6 @@
   use_temperature: false
   editor_model_name: azure/gpt-4o
   editor_edit_format: editor-diff
+  system_prompt_prefix: "Formatting re-enabled. "
 
   
\ No newline at end of file