diff --git a/tests/conftest.py b/tests/conftest.py
index dfef1c6..afa3671 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -13,6 +13,7 @@
 
 
 TEST_DIR = Path(__file__).resolve().parent
+CTYPESGEN_DIR = TEST_DIR.parent
 COMMON_DIR = TEST_DIR/"common"
 TMP_DIR = TEST_DIR/"tmp"
 
diff --git a/tests/testsuite.py b/tests/testsuite.py
index 8d637a6..78aec3b 100755
--- a/tests/testsuite.py
+++ b/tests/testsuite.py
@@ -29,6 +29,7 @@
 import math
 import unittest
 import subprocess
+from pathlib import Path
 from contextlib import (
     redirect_stdout,
     redirect_stderr,
@@ -44,6 +45,7 @@
     ctypesgen_wrapper,
     module_from_code,
     TMP_DIR,
+    CTYPESGEN_DIR,
     CLEANUP_OK,
 )
 from . import json_expects
@@ -1064,14 +1066,15 @@ def tearDownClass(cls):
         cls.outpath.unlink()
     
     def test_content(self):
+        # FIXME the double backslash is actually wrong -- maybe we should remove the R-string prefix, as python seems to auto-escape as necessary
         exp_docstring = R"""
 Auto-generated by:
 ctypesgen.api_main(
 {'library': 'c',
- 'output': PosixPath('./tests/tmp/apimain_stdio.py'),
+ 'output': %s,
  'symbol_rules': ['if_needed=__\\w+'],
  'system_headers': ['stdio.h']}
 )
-"""
+""" % (repr(self.outpath).replace(str(CTYPESGEN_DIR), "."), )
         self.assertEqual(self.module.__doc__, exp_docstring)
         self.assertTrue(hasattr(self.module, "printf"))