diff --git a/docs/book/src/reference/glossary.md b/docs/book/src/reference/glossary.md
index 7754f235d9e0..a1dc85290a91 100644
--- a/docs/book/src/reference/glossary.md
+++ b/docs/book/src/reference/glossary.md
@@ -56,6 +56,9 @@ Cluster API Provider Hetzner
 ### CAPIBM
 Cluster API Provider IBM Cloud
 
+### CAPM3
+Cluster API Provider Metal3
+
 ### CAPN
 Cluster API Provider Nested