+## Rust version requirements
+
+The MSRV (Minimum Supported Rust Version) is 1.32.0 . If/when this changes,
+it will be noted in the changelog, and the crate semver will be updated. So
+downstream projects should depend upon e.g. `spake2 = "0.2"` to avoid picking
+up new versions that would require a newer compiler.
+
+SRP-v0.4.1 actually works with rustc-1.31.1, but this will probably be
+changed in the next release.
+
+SPAKE2 required rustc-1.32 beginning with spake2-v0.2.0 .
+
+Our CI scripts check all builds against a pinned version of rustc to test the
+intended MSRV. Sometimes upstream dependencies make surprising changes that
+could require a newer version of rustc, without changes to the source code in
+this repository, but hopefully this won't happen very frequently.
+