diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 1852d8d80..5e99950fd 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -273,7 +273,7 @@ class Coder:
         ]
         if self.abs_fnames:
             files_messages += [
-                dict(role="system", content=self.gpt_prompts.system_reminder),
+                dict(role="system", content=self.fmt_system_reminder()),
             ]
 
         return files_messages
@@ -355,6 +355,25 @@ class Coder:
 
         return self.send_new_user_message(inp)
 
+    num_ticks = 4
+
+    def fmt_system_reminder(self):
+        prompt = self.gpt_prompts.system_reminder
+        num_ticks = self.num_ticks
+
+        explain = f"""
+You *MUST* use {num_ticks} backticks, because some files contain {num_ticks-1} backticks already!"""
+
+        fence = "`" * num_ticks
+
+        prompt = prompt.format(
+            num_ticks=num_ticks,
+            fence=fence,
+            num_ticks_explanation=explain,
+        )
+
+        return prompt
+
     def send_new_user_message(self, inp):
         self.cur_messages += [
             dict(role="user", content=inp),
@@ -362,7 +381,7 @@ class Coder:
 
         main_sys = self.gpt_prompts.main_system
         if self.main_model.max_context_tokens > 4 * 1024:
-            main_sys += "\n" + self.gpt_prompts.system_reminder
+            main_sys += "\n" + self.fmt_system_reminder()
 
         messages = [
             dict(role="system", content=main_sys),
diff --git a/aider/coders/wholefile_prompts.py b/aider/coders/wholefile_prompts.py
index eaf1f3e9b..26680098c 100644
--- a/aider/coders/wholefile_prompts.py
+++ b/aider/coders/wholefile_prompts.py
@@ -14,19 +14,19 @@ Once you understand the request you MUST:
 3. If changes are needed, output a copy of each file that needs changes.
 """
 
-    system_reminder = """
-To return code you MUST use this *file listing* format:
+    system_reminder = """To return code you MUST use this *file listing* format:
 
 path/to/filename.js
-```javascript
+{fence}javascript
 // entire file content goes in the
 // triple backticked fenced block
-```
+{fence}
 
 Every *file listing* MUST use this format:
 - First line: the filename with any required path!
-- Second line: opening triple backtick fence with the correct code language.
-- Final line: closing triple backtick fence.
+- Second line: opening {num_ticks} backtick fence with the correct code language.
+- Final line: closing {num_ticks} backtick fence.
+{num_ticks_explanation}
 
 To suggest changes to a file you MUST return a *file listing* that contains the entire content of the file.
 Create a new file you MUST return a *file listing* which includes an appropriate filename, including any required path.
diff --git a/aider/utils.py b/aider/utils.py
index e23d6b866..10fdc5a07 100644
--- a/aider/utils.py
+++ b/aider/utils.py
@@ -6,7 +6,7 @@ from .dump import dump  # noqa: F401
 def quoted_file(fname, display_fname, number=False):
     prompt = "\n"
     prompt += display_fname
-    prompt += "\n```\n"
+    prompt += "\n````\n"
     file_content = Path(fname).read_text()
     lines = file_content.splitlines()
     for i, line in enumerate(lines, start=1):
@@ -14,7 +14,7 @@ def quoted_file(fname, display_fname, number=False):
             prompt += f"{i:4d} "
         prompt += line + "\n"
 
-    prompt += "```\n"
+    prompt += "````\n"
     return prompt