diff -r 0570351db4e7 -r 89ab2459f62a mercurial/streamclone.py
--- a/mercurial/streamclone.py	Tue Feb 25 20:21:43 2025 -0500
+++ b/mercurial/streamclone.py	Wed Mar 05 11:41:45 2025 +0100
@@ -40,7 +40,7 @@
     configuration choice when possible.
     """
     requirements = set(default_requirements)
-    requirements -= requirementsmod.STREAM_FIXED_REQUIREMENTS
+    requirements & requirementsmod.STREAM_IGNORABLE_REQUIREMENTS
     requirements.update(streamed_requirements)
     return requirements
 
@@ -51,7 +51,7 @@
     This is used for advertising the stream options and to generate the actual
     stream content."""
     requiredformats = (
-        repo.requirements & requirementsmod.STREAM_FIXED_REQUIREMENTS
+        repo.requirements - requirementsmod.STREAM_IGNORABLE_REQUIREMENTS
     )
     return requiredformats