diff --git a/hgsql.py b/hgsql.py
index acff4d07af..f5072514bf 100644
--- a/hgsql.py
+++ b/hgsql.py
@@ -34,7 +34,9 @@ INITIAL_SYNC_FORCE = 'force'
 initialsync = INITIAL_SYNC_NORMAL
 
 cls = localrepo.localrepository
-for reqs in ['supportedformats', 'openerreqs', '_basesupported']:
+# Do NOT add hgsql to localrepository.supportedformats. Doing that breaks
+# streaming clones.
+for reqs in ['openerreqs', '_basesupported']:
     getattr(cls, reqs).add('hgsql')
 
 def newreporequirements(orig, repo):
diff --git a/tests/test-requires.t b/tests/test-requires.t
index 28d8a21384..b1f252f6d0 100644
--- a/tests/test-requires.t
+++ b/tests/test-requires.t
@@ -14,6 +14,8 @@
   $ hg pull -q ../client
 
 Test that hgsql is a requirement
+  $ grep hgsql .hg/requires
+  hgsql
   $ hg log -r tip --config extensions.hgsql=!
   abort: repository requires features unknown to this Mercurial: hgsql!
   (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
@@ -25,3 +27,9 @@ Test that hgsql is a requirement
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     x
   
+
+Ensure streaming clones to non-hgsql repos work
+  $ cd ..
+  $ hg clone --config extensions.hgsql=! --config ui.ssh='python "$TESTDIR/dummyssh"' --uncompressed ssh://user@dummy/master client2 | grep "streaming all changes"
+  streaming all changes
+