diff --git a/mercurial/bundlecaches.py b/mercurial/bundlecaches.py
--- a/mercurial/bundlecaches.py
+++ b/mercurial/bundlecaches.py
@@ -136,7 +136,7 @@ class bundlespec:
         b'cg.version': b'02',
         b'obsolescence': False,
         b'phases': False,
-        b"stream": "v2",
+        b"stream": b"v2",
         b'tagsfnodescache': False,
         b'revbranchcache': False,
     },
@@ -145,7 +145,7 @@ class bundlespec:
         b'cg.version': b'03',
         b'obsolescence': False,
         b'phases': False,
-        b"stream": "v3-exp",
+        b"stream": b"v3-exp",
         b'tagsfnodescache': False,
         b'revbranchcache': False,
     },
diff --git a/tests/test-stream-bundle-v2.t b/tests/test-stream-bundle-v2.t
--- a/tests/test-stream-bundle-v2.t
+++ b/tests/test-stream-bundle-v2.t
@@ -74,6 +74,23 @@ The extension requires a repo (currently
   none-v2;stream=v3-exp;requirements%3Dgeneraldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog (stream-v3 zstd no-rust !)
   none-v2;stream=v3-exp;requirements%3Dgeneraldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog (stream-v3 rust !)
 
+  $ hg bundle -a --type="none-$bundle_format" bundle.hg
+  $ hg debugbundle bundle.hg
+  Stream params: {}
+  stream2 -- {bytecount: 1693, filecount: 12, requirements: generaldelta%2Crevlogv1%2Csparserevlog} (mandatory: True) (stream-v2 no-zstd !)
+  stream2 -- {bytecount: 1693, filecount: 12, requirements: generaldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog} (mandatory: True) (stream-v2 zstd no-rust !)
+  stream2 -- {bytecount: 1819, filecount: 14, requirements: generaldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog} (mandatory: True) (stream-v2 rust !)
+  stream3-exp -- {requirements: generaldelta%2Crevlogv1%2Csparserevlog} (mandatory: True) (stream-v3 no-zstd !)
+  stream3-exp -- {requirements: generaldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog} (mandatory: True) (stream-v3 zstd no-rust !)
+  stream3-exp -- {requirements: generaldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog} (mandatory: True) (stream-v3 rust !)
+  $ hg debugbundle --spec bundle.hg
+  none-v2;stream=v2;requirements%3Dgeneraldelta%2Crevlogv1%2Csparserevlog (stream-v2 no-zstd !)
+  none-v2;stream=v2;requirements%3Dgeneraldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog (stream-v2 zstd no-rust !)
+  none-v2;stream=v2;requirements%3Dgeneraldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog (stream-v2 rust !)
+  none-v2;stream=v3-exp;requirements%3Dgeneraldelta%2Crevlogv1%2Csparserevlog (stream-v3 no-zstd !)
+  none-v2;stream=v3-exp;requirements%3Dgeneraldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog (stream-v3 zstd no-rust !)
+  none-v2;stream=v3-exp;requirements%3Dgeneraldelta%2Crevlog-compression-zstd%2Crevlogv1%2Csparserevlog (stream-v3 rust !)
+
 Test that we can apply the bundle as a stream clone bundle
 
   $ cat > .hg/clonebundles.manifest << EOF