diff --git a/lib/preopt/Cargo.toml b/lib/preopt/Cargo.toml
index 52dd0d8902..c2c6ee46fd 100644
--- a/lib/preopt/Cargo.toml
+++ b/lib/preopt/Cargo.toml
@@ -6,7 +6,7 @@ description = "Support for optimizations in Cranelift"
 license = "Apache-2.0 WITH LLVM-exception"
 documentation = "https://cranelift.readthedocs.io/"
 repository = "https://github.com/CraneStation/cranelift"
-categories = ["no_std"]
+categories = ["no-std"]
 readme = "README.md"
 keywords = ["optimize", "compile", "compiler", "jit"]
 
@@ -24,4 +24,4 @@ core = ["cranelift-codegen/core"]
 
 [badges]
 maintenance = { status = "experimental" }
-travis-ci = { repository = "CraneStation/cranelift" }
\ No newline at end of file
+travis-ci = { repository = "CraneStation/cranelift" }