diff --git a/product_docs/docs/tpa/23/reference/efm.mdx b/product_docs/docs/tpa/23/reference/efm.mdx
index 678347600e8..17e5c0b40d1 100644
--- a/product_docs/docs/tpa/23/reference/efm.mdx
+++ b/product_docs/docs/tpa/23/reference/efm.mdx
@@ -57,7 +57,10 @@ restart EFM to activate the changes.
 ### EFM witness
 
 TPA will install and configure EFM as witness on instances whose `role`
-contains `efm-witness`.
+contains `efm-witness`. For such instances the `upstream` property must be specified to point
+to the designated primary database instance.
+
+
 
 ### Repmgr