diff --git a/mcpp.toml b/mcpp.toml
index 5f2ae82..40ba6e9 100644
--- a/mcpp.toml
+++ b/mcpp.toml
@@ -27,9 +27,16 @@
 [package]
 namespace   = "mcpplibs"
 name        = "std-freestanding"
-version     = "0.5.0"
+version     = "0.5.1"
 description = "The freestanding subset of the C++ standard library as a module — import mcpplibs.std.freestanding"
 license     = "Apache-2.0"
+
+# The C++ layer, supplied as a subset rather than as a whole standard library.
+#
+# The distinction needs no capability of its own: this package declares no
+# `[package] std-module`, and that absence is what tells the engine `import
+# std` is not available here while `import mcpplibs.std.freestanding` is.
+provides    = ["mcpp:c++-abi=freestanding"]
 authors     = ["mcpplibs"]
 repo        = "https://github.com/mcpplibs/std-freestanding"