diff --git a/src/Server/TextDocument.php b/src/Server/TextDocument.php
index 2e8e4bf..982a245 100644
--- a/src/Server/TextDocument.php
+++ b/src/Server/TextDocument.php
@@ -221,15 +221,18 @@ class TextDocument
                         return [];
                     }
                 }
-                $refDocuments = yield Promise\all(array_map(
-                    [$this->documentLoader, 'getOrLoad'],
-                    $this->index->getReferenceUris($fqn)
-                ));
-                foreach ($refDocuments as $document) {
-                    $refs = $document->getReferenceNodesByFqn($fqn);
-                    if ($refs !== null) {
-                        foreach ($refs as $ref) {
-                            $locations[] = Location::fromNode($ref);
+                $referenceUris = $this->index->getReferenceUris($fqn);
+                if (!empty($referenceUris)) {
+                    $refDocuments = yield Promise\all(array_map(
+                        [$this->documentLoader, 'getOrLoad'],
+                        $referenceUris
+                    ));
+                    foreach ($refDocuments as $document) {
+                        $refs = $document->getReferenceNodesByFqn($fqn);
+                        if ($refs !== null) {
+                            foreach ($refs as $ref) {
+                                $locations[] = Location::fromNode($ref);
+                            }
                         }
                     }
                 }