diff --git a/src/CompletionProvider.php b/src/CompletionProvider.php
index f7181a6..2b34d3f 100644
--- a/src/CompletionProvider.php
+++ b/src/CompletionProvider.php
@@ -278,7 +278,7 @@ class CompletionProvider
                         } elseif (!$isAliased) {
                             continue;
                         }
-                    } elseif ($fqnStartsWithPrefix && $class->isFullyQualifiedName()) {
+                    } elseif ($fqnStartsWithPrefix && $class instanceof Node\QualifiedName && $class->isFullyQualifiedName()) {
                         $fqn = '\\' . $fqn;
                     }