diff --git a/CHANGES.txt b/CHANGES.txt
index 04274279d7..2b67532c97 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -135,6 +135,7 @@
  * Add the ability to disable bulk loading of SSTables (CASSANDRA-18781)
  * Clean up obsolete functions and simplify cql_version handling in cqlsh (CASSANDRA-18787)
 Merged from 5.0:
+ * Fix unparseable YAML in default cassandra.yaml when uncommented for downstream tooling (CASSANDRA-20359)
  * Avoid fetching entire partitions on unresolved static rows in RFP when no static column predicates exist (CASSANDRA-20243)
  * Avoid indexing empty values for non-literals and types that do not allow them (CASSANDRA-20313)
  * Fix incorrect results of min / max in-built functions on clustering columns in descending order (CASSANDRA-20295)
diff --git a/conf/cassandra.yaml b/conf/cassandra.yaml
index 52223a1262..9f8f24b584 100644
--- a/conf/cassandra.yaml
+++ b/conf/cassandra.yaml
@@ -196,12 +196,12 @@ batchlog_replay_throttle: 1024KiB
 #   Please increase system_auth keyspace replication factor if you use this authenticator.
 #   If using PasswordAuthenticator, CassandraRoleManager must also be used (see below)
 authenticator:
-  class_name : AllowAllAuthenticator
+  class_name: AllowAllAuthenticator
 # MutualTlsAuthenticator can be configured using the following configuration. One can add their own validator
 # which implements MutualTlsCertificateValidator class and provide logic for extracting identity out of certificates
 # and validating certificates.
-#  class_name : org.apache.cassandra.auth.MutualTlsAuthenticator
-#  parameters :
+#  class_name: org.apache.cassandra.auth.MutualTlsAuthenticator
+#  parameters:
 #    validator_class_name: org.apache.cassandra.auth.SpiffeCertificateValidator
 
 # Authorization backend, implementing IAuthorizer; used to limit access/provide permissions
@@ -1016,13 +1016,13 @@ listen_address: localhost
 # Internode authentication backend, implementing IInternodeAuthenticator;
 # used to allow/disallow connections from peer nodes.
 #internode_authenticator:
-#  class_name : org.apache.cassandra.auth.AllowAllInternodeAuthenticator
-#  parameters :
+#  class_name: org.apache.cassandra.auth.AllowAllInternodeAuthenticator
+#  parameters:
 # MutualTlsInternodeAuthenticator can be configured using the following configuration.One can add their own validator
 # which implements MutualTlsCertificateValidator class and provide logic for extracting identity out of certificates
 # and validating certificates.
-#  class_name : org.apache.cassandra.auth.MutualTlsInternodeAuthenticator
-#  parameters :
+#  class_name: org.apache.cassandra.auth.MutualTlsInternodeAuthenticator
+#  parameters:
 #    validator_class_name: org.apache.cassandra.auth.SpiffeCertificateValidator
 #    trusted_peer_identities: "spiffe1,spiffe2"
 #    node_identity: "spiffe1"
diff --git a/conf/cassandra_latest.yaml b/conf/cassandra_latest.yaml
index ce1d97c476..f8d791b26f 100644
--- a/conf/cassandra_latest.yaml
+++ b/conf/cassandra_latest.yaml
@@ -199,12 +199,12 @@ batchlog_endpoint_strategy: dynamic_remote
 #   Please increase system_auth keyspace replication factor if you use this authenticator.
 #   If using PasswordAuthenticator, CassandraRoleManager must also be used (see below)
 authenticator:
-  class_name : AllowAllAuthenticator
+  class_name: AllowAllAuthenticator
 # MutualTlsAuthenticator can be configured using the following configuration. One can add their own validator
 # which implements MutualTlsCertificateValidator class and provide logic for extracting identity out of certificates
 # and validating certificates.
-#  class_name : org.apache.cassandra.auth.MutualTlsAuthenticator
-#  parameters :
+#  class_name: org.apache.cassandra.auth.MutualTlsAuthenticator
+#  parameters:
 #    validator_class_name: org.apache.cassandra.auth.SpiffeCertificateValidator
 
 # Authorization backend, implementing IAuthorizer; used to limit access/provide permissions
@@ -1005,13 +1005,13 @@ listen_address: localhost
 # Internode authentication backend, implementing IInternodeAuthenticator;
 # used to allow/disallow connections from peer nodes.
 #internode_authenticator:
-#  class_name : org.apache.cassandra.auth.AllowAllInternodeAuthenticator
-#  parameters :
+#  class_name: org.apache.cassandra.auth.AllowAllInternodeAuthenticator
+#  parameters:
 # MutualTlsInternodeAuthenticator can be configured using the following configuration.One can add their own validator
 # which implements MutualTlsCertificateValidator class and provide logic for extracting identity out of certificates
 # and validating certificates.
-#  class_name : org.apache.cassandra.auth.MutualTlsInternodeAuthenticator
-#  parameters :
+#  class_name: org.apache.cassandra.auth.MutualTlsInternodeAuthenticator
+#  parameters:
 #    validator_class_name: org.apache.cassandra.auth.SpiffeCertificateValidator
 #    trusted_peer_identities: "spiffe1,spiffe2"
 #    node_identity: "spiffe1"