diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 06656b5..c773571 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -29,7 +29,7 @@ on:
 env:
   XLINGS_VERSION: v2026.10.26.1
   XLINGS_NON_INTERACTIVE: '1'
-  MCPP_VERSION: 2026.11.5.1
+  MCPP_VERSION: 2026.11.9.1
   LLVM: llvm@23.1.3
 
 jobs:
diff --git a/.github/workflows/release-binaries.yml b/.github/workflows/release-binaries.yml
index d693742..61cd462 100644
--- a/.github/workflows/release-binaries.yml
+++ b/.github/workflows/release-binaries.yml
@@ -33,9 +33,9 @@ env:
   RELEASE_TAG: ${{ github.event.inputs.tag }}
   ASSET_REVISION: ${{ github.event.inputs.asset_revision || '' }}
   MCPP_SOURCE_REF: ${{ github.event.inputs.mcpp_ref || vars.MCPP_SOURCE_REF || '' }}
-  # 2026.11.3.1 compiles the std module with the selected platform's flags.
+  # 2026.11.9.1: openkal-run states its implementation as a capability with defaults.
   # mcpp_ref supplies the candidate until this release is installable.
-  MCPP_VERSION: 2026.11.3.1
+  MCPP_VERSION: 2026.11.9.1
   # The platform whose hosted arrangement the programs are built over, named by
   # the dispatch beside the tag: a tag's tools pin exact implementations, and the
   # platform is the one whose version group holds them (0.1.4: 0.18.0; 0.1.5:
diff --git a/README.md b/README.md
index 3c3a127..04afc03 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,14 @@ image starts; a binding makes each call from a program of the system in it and
 restores the caller's after it (`okrun_call_enter`, `okrun_call_leave`). The
 `fpstate` example and the `bind` example check it on every system.
 
+Version 0.5.4 states the implementation of openkal the runner binds as a
+capability with a default per system rather than a dependency per system:
+`requires = ["mcpp:kernel-abi=openkal"]` with `[defaults."mcpp:kernel-abi=openkal"]`
+naming openkal-linux, openkal-macos and openkal-windows (mcpp 2026.11.9.1). An
+implementation the graph already has --- the consumer's own, or the one its
+platform adds, such as openkal-posix on another system --- is the one bound,
+without a patch of this package.
+
 ## An image
 
 ```sh
diff --git a/bind/mcpp.toml b/bind/mcpp.toml
index 58ebbc1..a848695 100644
--- a/bind/mcpp.toml
+++ b/bind/mcpp.toml
@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-bind"
-version     = "0.5.3"
+version     = "0.5.4"
 # `mcpp::xpkg_request', `mcpp::decision' (protocol 15).
 mcpp        = ">=2026.10.1.3"
 description = "A build plugin: a library published as an ok image (.okso) and a C header is called from a program of any system, through a binding generated from the header and libokrun."
diff --git a/ld/mcpp.toml b/ld/mcpp.toml
index 4e564ab..5d17c60 100644
--- a/ld/mcpp.toml
+++ b/ld/mcpp.toml
@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-ld"
-version     = "0.5.3"
+version     = "0.5.4"
 description = "libokld: the ok format (openkal image format) --- its definition, a reader of bytes, a checker, a signer, and a loader. Freestanding: no C library, no exceptions."
 license     = "Apache-2.0"
 authors     = ["mcpplibs"]
diff --git a/run/mcpp.toml b/run/mcpp.toml
index 6ffe153..64c604e 100644
--- a/run/mcpp.toml
+++ b/run/mcpp.toml
@@ -1,11 +1,17 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-run"
-version     = "0.5.3"
+version     = "0.5.4"
 description = "libokrun: the runner's core --- an ok image's names bound to this process's one openkal implementation, in the image's calling convention, and its entry entered."
 license     = "Apache-2.0"
 authors     = ["mcpplibs"]
 repo        = "https://github.com/mcpplibs/openkal-image"
+# `[defaults]' (mcpp 2026.11.9.1, SPEC-002 §3.7).
+mcpp        = ">=2026.11.9.1"
+# The runner binds an image's names to this process's one implementation of
+# openkal: whichever the graph has --- the consumer's, or the one its
+# platform adds --- else the default of the system below.
+requires    = ["mcpp:kernel-abi=openkal"]
 
 [targets.okrun]
 kind = "lib"
@@ -14,14 +20,10 @@ kind = "lib"
 openkal = "^0.24.0"
 openkal-ld = { path = "../ld" }
 
-[target.linux.dependencies]
-openkal-linux = "^0.25.0"
-
-[target.macos.dependencies]
-openkal-macos = "^0.22.1"
-
-[target.windows.dependencies]
-openkal-windows = "^0.20.0"
+[defaults."mcpp:kernel-abi=openkal"]
+linux   = "openkal-linux@^0.25.0"
+macos   = "openkal-macos@^0.22.1"
+windows = "openkal-windows@^0.20.0"
 
 # The interfaces each system's implementation provides decide one unit: where
 # openkal.space is provided its names are bound, and elsewhere an image that
diff --git a/tools/mcpp.toml b/tools/mcpp.toml
index 63399e3..71b2689 100644
--- a/tools/mcpp.toml
+++ b/tools/mcpp.toml
@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-tools"
-version     = "0.5.3"
+version     = "0.5.4"
 description = "okrun, which runs an ok image on this system, and okld, the format's tool on a build machine (check, note, sign, inspect)."
 license     = "Apache-2.0"
 authors     = ["mcpplibs"]