diff --git a/test/modules/proxy/test_06_interim_resp.py b/test/modules/proxy/test_06_interim_resp.py
index 2382649aff..05e88a84fd 100644
--- a/test/modules/proxy/test_06_interim_resp.py
+++ b/test/modules/proxy/test_06_interim_resp.py
@@ -107,8 +107,10 @@ class TestStatusLineCR:
             f"bare CR in status line: {status_line!r}"
         assert b"X-Foobar" not in status_line, \
             f"attacker text in status line: {status_line!r}"
+        # Prevent 'f-string expression part cannot include a backslash'
+        hide_backslash = b'\\r\\n\\r\\n'
         assert b"X-Foobar" not in raw.split(b"\r\n\r\n")[0], \
-            f"injected header in response headers: {raw.split(b'\\r\\n\\r\\n')[0]!r}"
+            f"injected header in response headers: {raw.split(hide_backslash)[0]!r}"
 
         env.httpd_error_log.ignore_recent(
             lognos=["AH00957", "AH01106", "AH01114"]