diff --git a/doc/api/os.md b/doc/api/os.md
index 094a5170a1662f..4a1007f74db002 100644
--- a/doc/api/os.md
+++ b/doc/api/os.md
@@ -460,8 +460,8 @@ added: v18.9.0
 
 * Returns {string}
 
-Returns the machine type as a string, such as `arm`, `aarch64`, `mips`,
-`mips64`, `ppc64`, `ppc64le`, `s390`, `s390x`, `i386`, `i686`, `x86_64`.
+Returns the machine type as a string, such as `arm`, `arm64`, `aarch64`,
+`mips`, `mips64`, `ppc64`, `ppc64le`, `s390`, `s390x`, `i386`, `i686`, `x86_64`.
 
 On POSIX systems, the machine type is determined by calling
 [`uname(3)`][]. On Windows, `RtlGetVersion()` is used, and if it is not