diff --git a/src/Visitor/Php/SourceLocationContainerVisitor.php b/src/Visitor/Php/SourceLocationContainerVisitor.php
index e2f7062..dbdf6ab 100644
--- a/src/Visitor/Php/SourceLocationContainerVisitor.php
+++ b/src/Visitor/Php/SourceLocationContainerVisitor.php
@@ -51,7 +51,7 @@ public function enterNode(Node $node)
 
         if ($node instanceof Node\Stmt\UseUse) {
             $key = isset($node->alias) ? $node->alias : $node->name->parts[count($node->name->parts) - 1];
-            $this->useStatements[$key] = implode('\\', $node->name->parts);
+            $this->useStatements[(string) $key] = implode('\\', $node->name->parts);
 
             return;
         }
diff --git a/src/Visitor/Php/Symfony/AbstractFormType.php b/src/Visitor/Php/Symfony/AbstractFormType.php
index e99d0ab..93f32b2 100644
--- a/src/Visitor/Php/Symfony/AbstractFormType.php
+++ b/src/Visitor/Php/Symfony/AbstractFormType.php
@@ -34,11 +34,11 @@ abstract class AbstractFormType extends BasePHPVisitor implements NodeVisitor
     public function enterNode(Node $node)
     {
         if ($node instanceof Node\Expr\MethodCall) {
-            if (!is_string($node->name)) {
+            if (!is_string($node->name) && !$node->name instanceof Node\Identifier) {
                 return;
             }
 
-            $name = strtolower($node->name);
+            $name = strtolower((string) $node->name);
             if ('setdefaults' === $name || 'replacedefaults' === $name || 'setdefault' === $name) {
                 $this->parseDefaultsCall($node);