diff --git a/Cargo.toml b/Cargo.toml
index 014cce1..cbc5a5e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,7 @@ license = "CC0-1.0"
 repository = "https://code.ciph.re/isis/curve25519-dalek"
 homepage = "https://code.ciph.re/isis/curve25519-dalek"
 documentation = "https://docs.rs/curve25519-dalek"
+categories = ["cryptography", "no-std"]
 keywords = ["cryptography", "curve25519", "elliptic", "curve", "ECC"]
 description = "A low-level cryptographic library for point, group, field, and scalar operations on a curve isomorphic to the twisted Edwards curve defined by -x²+y² = 1 - 121665/121666 x²y² over GF(2²⁵⁵ - 19)."
 exclude = [