diff --git a/.github/workflows/release-binaries.yml b/.github/workflows/release-binaries.yml
index e9c9655..ff87f6a 100644
--- a/.github/workflows/release-binaries.yml
+++ b/.github/workflows/release-binaries.yml
@@ -14,9 +14,9 @@ on:
         description: "The release tag the binaries are built from and attached to (e.g. 0.1.3)"
         required: true
       platform:
-        description: "The openkal-platform whose hosted arrangement builds the tools: the one whose version group holds the implementations the tag pins (0.1.5: 0.19.0; 0.1.6: 0.19.1; 0.1.7: 0.19.2; 0.1.8: 0.20.0; 0.1.9: 0.20.1)"
+        description: "The openkal-platform whose hosted arrangement builds the tools: the one whose version group holds the implementations the tag pins (0.1.5: 0.19.0; 0.1.6: 0.19.1; 0.1.7: 0.19.2; 0.1.8: 0.20.0; 0.1.9: 0.20.1; 0.3.0: 0.21.0)"
         required: true
-        default: "0.19.0"
+        default: "0.21.0"
       mcpp_ref:
         description: "Branch of mcpp-community/mcpp to build with (empty = the released mcpp)"
         required: false
@@ -27,11 +27,14 @@ permissions:
 
 env:
   MCPP_SOURCE_REF: ${{ github.event.inputs.mcpp_ref || vars.MCPP_SOURCE_REF || '' }}
-  MCPP_VERSION: 2026.10.30.1
+  # 2026.11.2.1: openkal-platform 0.21.0's C library, openkal-musl 0.26.0,
+  # embeds its allocator (`embed') and states mcpp >= 2026.11.
+  MCPP_VERSION: 2026.11.2.1
   # 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:
-  # 0.19.0, openkal-linux 0.19.0; 0.1.6: 0.19.1; 0.1.7: 0.19.2; 0.1.8: 0.20.0; 0.1.9: 0.20.1).
+  # 0.19.0, openkal-linux 0.19.0; 0.1.6: 0.19.1; 0.1.7: 0.19.2; 0.1.8: 0.20.0; 0.1.9: 0.20.1;
+  # 0.3.0: 0.21.0).
   PLATFORM_VERSION: ${{ github.event.inputs.platform }}
   XLINGS_VERSION: v2026.10.26.1
   XLINGS_NON_INTERACTIVE: '1'