diff --git a/PLATFORMS.md b/PLATFORMS.md
index edaa7edc20..c891c17797 100644
--- a/PLATFORMS.md
+++ b/PLATFORMS.md
@@ -58,6 +58,7 @@ In this policy, the words "must" and "must not" specify absolute requirements th
 - aarch64 for Apple iOS and tvOS (CMake `-DPLATFORM=OS64` and `TVOS`)
 - arm64, arm (32 bit), x86, x86_64, riscv32, riscv64 for Zephyr
 - armhf/ARM7 emulation on Ubuntu
+- amd64 for Alpine Linux
 
 ### Tier 3