diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index c4ba39bc985..9a597f187bf 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -119,6 +119,12 @@ Upgrading from Solr 4.x
 * The "checkIntegrityAtMerge" option in solrconfig.xml is now a No-Op and should be removed
   from any solrconfig.xml files -- these integrity checks are now done automatically at a very
   low level during the segment merging process.  See SOLR-6834 for more details.
+  
+* SimplePostTool (post.jar) no longer defaults to collection1, making either of core/collection
+  name or update URL mandatory. An existing call without an explicit update URL needs to now
+  have the core/collection name passed as "-Dc=<collection/core name>" e.g.:
+    java -jar -Dc=<collection_name> post.jar *.xml (new call with collection name)
+  See SOLR-6852 for more details.
 
 Detailed Change List
 ----------------------
diff --git a/solr/README.txt b/solr/README.txt
index 00f5e97c8da..55d9bd3e244 100644
--- a/solr/README.txt
+++ b/solr/README.txt
@@ -87,7 +87,7 @@ To add documents to the index, use the post.jar (or post.sh script) in
 the example/exampledocs subdirectory (while Solr is running), for example:
 
      cd example/exampledocs
-     java -jar -Dc=<collection_name>post.jar *.xml
+     java -jar -Dc=<collection_name> post.jar *.xml
 Or:  sh post.sh *.xml
 
 For more information about Solr examples please read...