diff --git a/source/includes/fact-5.1-reconfig-CWWC-validation.rst b/source/includes/fact-5.1-reconfig-CWWC-validation.rst
new file mode 100644
index 00000000000..27e05f48a79
--- /dev/null
+++ b/source/includes/fact-5.1-reconfig-CWWC-validation.rst
@@ -0,0 +1,6 @@
+Starting in MongoDB 5.1, you must set the
+:ref:`Cluster Wide Write Concern (CWWC) <set_global_default_write_concern>` 
+prior to issuing any :method:`reconfigs <rs.reconfig()>` 
+that would otherwise change the 
+:ref:`default write concern <write-concern>` of the new 
+:term:`replica set` member.
\ No newline at end of file
diff --git a/source/reference/command/setDefaultRWConcern.txt b/source/reference/command/setDefaultRWConcern.txt
index a1a79d9a47d..3c1a282ef8c 100644
--- a/source/reference/command/setDefaultRWConcern.txt
+++ b/source/reference/command/setDefaultRWConcern.txt
@@ -308,6 +308,8 @@ The operation returns a document similar to the following:
      "operationTime" : Timestamp(1586290925, 1)
    }
 
+.. _set_global_default_write_concern:
+
 Set Global Default Read and Write Concern
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/source/release-notes/5.1-compatibility.txt b/source/release-notes/5.1-compatibility.txt
index 3ecf0ae0390..f2ae3937647 100644
--- a/source/release-notes/5.1-compatibility.txt
+++ b/source/release-notes/5.1-compatibility.txt
@@ -47,6 +47,11 @@ Shell Changes
 Replica Sets
 ------------
 
+``rs.reconfig`` Cluster Wide Write Concern Validation
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. include:: /includes/fact-5.1-reconfig-CWWC-validation.rst
+
 Arbiters
 ~~~~~~~~
 
diff --git a/source/release-notes/5.1.txt b/source/release-notes/5.1.txt
index d4203d1f360..242ad6723e5 100644
--- a/source/release-notes/5.1.txt
+++ b/source/release-notes/5.1.txt
@@ -125,6 +125,11 @@ For an example, see :ref:`validation-description-example`.
 Replica Sets
 ------------
 
+``rs.reconfig`` Cluster Wide Write Concern Validation
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. include:: /includes/fact-5.1-reconfig-CWWC-validation.rst
+
 ``storeFindAndModifyImagesInSideCollection`` Parameter
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~