diff --git a/9pm.py b/9pm.py
index aa7faea..5d34ebe 100755
--- a/9pm.py
+++ b/9pm.py
@@ -586,11 +586,12 @@ def agent_prompt(data, aborted):
             called = "called without arguments"
         lines.append(wrap(f"\"{test['name']}\" at \"{proj_relpath(test['case'])}\" "
                           f"{called} failed with:"))
+        lines.append("```")
         for failure in test['failures']:
-            lines.extend(f"  {line}" for line in failure)
+            lines.extend(failure)
             if len(failure) >= 40:
-                lines.append("  (more in the log)")
-        lines.append("")
+                lines.append("(more in the log)")
+        lines += ["```", ""]
 
     lines.append("Please help me investigate this.")
     if PROJECT.get('AGENT-HINTS'):
diff --git a/self_test/run.py b/self_test/run.py
index ae6509a..e3fbb5b 100755
--- a/self_test/run.py
+++ b/self_test/run.py
@@ -332,7 +332,7 @@ def test_agent_prompt(self):
         for expected in [
             '1 test failed running "self_test/suites/abort-suite.yaml" in project 9pm (git ',
             '"fail.sh" at "self_test/cases/fail.sh" called with arguments \'opt1\' failed with:',
-            "  not ok 1 - Dummy test fail",
+            "failed with: ``` not ok 1 - Dummy test fail ```",
             "The run was aborted at the first fatal failure.",
             "Please help me investigate this.",
         ]: