diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -1425,9 +1425,12 @@ coreconfigitem(
     default=False,
     experimental=True,
 )
+
+# Moving this on by default means we are confident about the scaling of phases.
+# This is not garanteed to be the case at the time this message is written.
 coreconfigitem(
     b'format',
-    b'internal-phase',
+    b'use-internal-phase',
     default=False,
     experimental=True,
 )
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -3662,7 +3662,7 @@ def newreporequirements(ui, createopts):
         requirements.discard(requirementsmod.REVLOGV1_REQUIREMENT)
         requirements.add(requirementsmod.REVLOGV2_REQUIREMENT)
     # experimental config: format.internal-phase
-    if ui.configbool(b'format', b'internal-phase'):
+    if ui.configbool(b'format', b'use-internal-phase'):
         requirements.add(requirementsmod.INTERNAL_PHASE_REQUIREMENT)
 
     # experimental config: format.exp-archived-phase
diff --git a/mercurial/requirements.py b/mercurial/requirements.py
--- a/mercurial/requirements.py
+++ b/mercurial/requirements.py
@@ -29,7 +29,7 @@ SPARSE_REQUIREMENT = b'exp-sparse'
 
 # Enables the internal phase which is used to hide changesets instead
 # of stripping them
-INTERNAL_PHASE_REQUIREMENT = b'internal-phase'
+INTERNAL_PHASE_REQUIREMENT = b'internal-phase-2'
 
 # Enables the internal phase which is used to hide changesets instead
 # of stripping them
diff --git a/tests/test-phases.t b/tests/test-phases.t
--- a/tests/test-phases.t
+++ b/tests/test-phases.t
@@ -879,7 +879,7 @@ Test for the "internal" phase
 
 Check we deny its usage on older repository
 
-  $ hg init no-internal-phase --config format.internal-phase=no
+  $ hg init no-internal-phase --config format.use-internal-phase=no
   $ cd no-internal-phase
   $ hg debugrequires | grep internal-phase
   [1]
@@ -900,10 +900,10 @@ Check we deny its usage on older reposit
 
 Check it works fine with repository that supports it.
 
-  $ hg init internal-phase --config format.internal-phase=yes
+  $ hg init internal-phase --config format.use-internal-phase=yes
   $ cd internal-phase
   $ hg debugrequires | grep internal-phase
-  internal-phase
+  internal-phase-2
   $ mkcommit A
   test-debug-phase: new rev 0:  x -> 1
   test-hook-close-phase: 4a2df7238c3b48766b5e22fafbb8a2f506ec8256:   -> draft
diff --git a/tests/test-shelve.t b/tests/test-shelve.t
--- a/tests/test-shelve.t
+++ b/tests/test-shelve.t
@@ -14,7 +14,7 @@
 
   $ cat <<EOF >> $HGRCPATH
   > [format]
-  > internal-phase = yes
+  > use-internal-phase = yes
   > EOF
 
 #endif
diff --git a/tests/test-shelve2.t b/tests/test-shelve2.t
--- a/tests/test-shelve2.t
+++ b/tests/test-shelve2.t
@@ -16,7 +16,7 @@
 
   $ cat <<EOF >> $HGRCPATH
   > [format]
-  > internal-phase = yes
+  > use-internal-phase = yes
   > EOF
 
 #endif