diff --git a/Changelog.md b/Changelog.md
index f63149a98..2cae446bb 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -45,6 +45,9 @@ a more pleasant experience, especially for users with larger databases.
 - **Fixed** some SPARQL endpoints by using `application/sparql-results+json`
   accept header for SPARQL requests
   ([#499](https://github.com/aws/graph-explorer/pull/499))
+- **Fixed** CORS issue for some SPARQL and Gremlin endpoints due to `queryId` in
+  the request headers ([#529](https://github.com/aws/graph-explorer/pull/529))
+  ([#499](https://github.com/aws/graph-explorer/pull/499))
 - **Fixed** text wrapping for labels in edge styling sidebar
   ([#499](https://github.com/aws/graph-explorer/pull/499))
 - **Fixed** potential error when the request body is very large by increasing
diff --git a/packages/graph-explorer/src/connector/gremlin/gremlinExplorer.ts b/packages/graph-explorer/src/connector/gremlin/gremlinExplorer.ts
index 2db7d6d81..6af4ad3d5 100644
--- a/packages/graph-explorer/src/connector/gremlin/gremlinExplorer.ts
+++ b/packages/graph-explorer/src/connector/gremlin/gremlinExplorer.ts
@@ -18,7 +18,7 @@ function _gremlinFetch(connection: ConnectionConfig, options: any) {
       "Content-Type": "application/json",
       Accept: "application/vnd.gremlin-v3.0+json",
     };
-    if (options?.queryId && connection?.proxyConnection === true) {
+    if (options?.queryId && connection.proxyConnection === true) {
       headers.queryId = options.queryId;
     }
 
diff --git a/packages/graph-explorer/src/connector/sparql/sparqlExplorer.ts b/packages/graph-explorer/src/connector/sparql/sparqlExplorer.ts
index b0d896d0d..7b23eb3ff 100644
--- a/packages/graph-explorer/src/connector/sparql/sparqlExplorer.ts
+++ b/packages/graph-explorer/src/connector/sparql/sparqlExplorer.ts
@@ -136,16 +136,17 @@ function _sparqlFetch(connection: ConnectionConfig, options?: any) {
   return async (queryTemplate: string) => {
     logger.debug(queryTemplate);
     const body = `query=${encodeURIComponent(queryTemplate)}`;
-    const headers = options?.queryId
-      ? {
-          accept: "application/sparql-results+json",
-          "Content-Type": "application/x-www-form-urlencoded",
-          queryId: options.queryId,
-        }
-      : {
-          accept: "application/sparql-results+json",
-          "Content-Type": "application/x-www-form-urlencoded",
-        };
+    const headers =
+      options?.queryId && connection.proxyConnection === true
+        ? {
+            accept: "application/sparql-results+json",
+            "Content-Type": "application/x-www-form-urlencoded",
+            queryId: options.queryId,
+          }
+        : {
+            accept: "application/sparql-results+json",
+            "Content-Type": "application/x-www-form-urlencoded",
+          };
     return fetchDatabaseRequest(connection, `${connection.url}/sparql`, {
       method: "POST",
       headers,