diff --git a/README.md b/README.md
index be719c9b2b..929ec1d8a9 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ YJIT - Yet Another Ruby JIT
 YJIT is a lightweight, minimalistic Ruby JIT built inside the CRuby/MRI binary.
 It lazily compiles code using a Basic Block Versioning (BBV) architecture. The target use case is that of servers running
 Ruby on Rails, an area where CRuby's MJIT has not yet managed to deliver speedups.
-To simplify development, we currently support only MacOS and Linux on x86-64, but an ARM64 backend
+To simplify development, we currently support only macOS and Linux on x86-64, but an ARM64 backend
 is part of future plans.
 This project is open source and falls under the same license as CRuby.