diff --git a/solr/solrj/src/java/org/apache/solr/client/solrj/impl/HttpJdkSolrClient.java b/solr/solrj/src/java/org/apache/solr/client/solrj/impl/HttpJdkSolrClient.java
index e3c40118d62..8fe0697878b 100644
--- a/solr/solrj/src/java/org/apache/solr/client/solrj/impl/HttpJdkSolrClient.java
+++ b/solr/solrj/src/java/org/apache/solr/client/solrj/impl/HttpJdkSolrClient.java
@@ -302,7 +302,9 @@ private PreparedRequest preparePutOrPost(
       ModifiableSolrParams requestParams = queryParams;
       queryParams = calculateQueryParams(urlParamNames, requestParams);
       queryParams.add(calculateQueryParams(solrRequest.getQueryParams(), requestParams));
-      bodyPublisher = HttpRequest.BodyPublishers.ofString(requestParams.toString());
+      // note the toQueryString() method adds a leading question mark which needs to be removed here
+      bodyPublisher =
+          HttpRequest.BodyPublishers.ofString(requestParams.toQueryString().substring(1));
     } else {
       bodyPublisher = HttpRequest.BodyPublishers.noBody();
     }