diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index 5dbe8eee0cd..0af7fdb958e 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -100,6 +100,9 @@ Upgrading from Solr 5.2
 
 * class TransformerWithContext is deprecated . Use DocTransformer directly
 
+* The "name" parameter in ADDREPLICA Collections API call has be deprecated. One cannot specify
+  the core name for a replica. See SOLR-7499 for more info.
+
 Detailed Change List
 ----------------------
 
@@ -232,6 +235,9 @@ Other Changes
 * SOLR-7629: Have RulesTest consider disk space limitations of where the test is
   being run (Christine Poerschke via Ramkumar Aiyengar)
 
+* The "name" parameter in ADDREPLICA Collections API call has be deprecated. One cannot specify
+  the core name for a replica. See SOLR-7499 for more info. (Varun Thacker, noble, Erick Erickson)
+
 ==================  5.2.1 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release
diff --git a/solr/core/src/java/org/apache/solr/cloud/OverseerCollectionProcessor.java b/solr/core/src/java/org/apache/solr/cloud/OverseerCollectionProcessor.java
index fb9c2af63a4..4df04ede8cc 100644
--- a/solr/core/src/java/org/apache/solr/cloud/OverseerCollectionProcessor.java
+++ b/solr/core/src/java/org/apache/solr/cloud/OverseerCollectionProcessor.java
@@ -2520,7 +2520,7 @@ public class OverseerCollectionProcessor implements Runnable, Closeable {
         String replicaName = collection + "_" + shard + "_replica" + replicaNum;
         boolean exists = false;
         for (Replica replica : slice.getReplicas()) {
-          if (replicaName.equals(replica.getStr("core"))) {
+          if (replicaName.equals(replica.getStr(CORE_NAME_PROP))) {
             exists = true;
             break;
           }
@@ -2529,6 +2529,17 @@ public class OverseerCollectionProcessor implements Runnable, Closeable {
         else break;
       }
       coreName = collection + "_" + shard + "_replica" + replicaNum;
+    } else {
+      //Validate that the core name is unique in that collection
+      for (Slice slice : coll.getSlices()) {
+        for (Replica replica : slice.getReplicas()) {
+          String replicaCoreName = replica.getStr(CORE_NAME_PROP);
+          if (coreName.equals(replicaCoreName)) {
+            throw new SolrException(ErrorCode.BAD_REQUEST, "Another replica with the same core name already exists" +
+                " for this collection");
+          }
+        }
+      }
     }
     ModifiableSolrParams params = new ModifiableSolrParams();
     
diff --git a/solr/core/src/test/org/apache/solr/cloud/CollectionsAPIDistributedZkTest.java b/solr/core/src/test/org/apache/solr/cloud/CollectionsAPIDistributedZkTest.java
index 2bdc29448c6..9d1cfd036f3 100644
--- a/solr/core/src/test/org/apache/solr/cloud/CollectionsAPIDistributedZkTest.java
+++ b/solr/core/src/test/org/apache/solr/cloud/CollectionsAPIDistributedZkTest.java
@@ -84,6 +84,7 @@ import org.junit.Test;
 
 import static org.apache.solr.cloud.OverseerCollectionProcessor.NUM_SLICES;
 import static org.apache.solr.common.cloud.ZkNodeProps.makeMap;
+import static org.apache.solr.common.cloud.ZkStateReader.CORE_NAME_PROP;
 import static org.apache.solr.common.cloud.ZkStateReader.MAX_SHARDS_PER_NODE;
 import static org.apache.solr.common.cloud.ZkStateReader.REPLICATION_FACTOR;
 
@@ -1143,8 +1144,23 @@ public class CollectionsAPIDistributedZkTest extends AbstractFullDistribZkTestBa
       NamedList<Object> coreStatus = status.getCoreStatus(newReplica.getStr("core"));
       String instanceDirStr = (String) coreStatus.get("instanceDir");
       assertEquals(Paths.get(instanceDirStr).toString(), instancePathStr);
-    }
 
+      //Test to make sure we can't create another replica with an existing core_name of that collection
+      String coreName = newReplica.getStr(CORE_NAME_PROP);
+      ModifiableSolrParams params = new ModifiableSolrParams();
+      params.set("action", "addreplica");
+      params.set("collection", collectionName);
+      params.set("shard", "shard1");
+      params.set("name", coreName);
+      QueryRequest request = new QueryRequest(params);
+      request.setPath("/admin/collections");
+      try {
+        client.request(request);
+        fail("AddReplica call should not have been successful");
+      } catch (SolrException e) {
+        assertTrue(e.getMessage().contains("Another replica with the same core name already exists for this collection"));
+      }
+    }
   }
 
   @Override