diff --git a/src/DefinitionResolver.php b/src/DefinitionResolver.php
index 1692c6e..426b552 100644
--- a/src/DefinitionResolver.php
+++ b/src/DefinitionResolver.php
@@ -42,7 +42,7 @@ class DefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return string
      */
-    public function getDeclarationLineFromNode(Node $node): string
+    public function getDeclarationLineFromNode($node): string
     {
         if ($node instanceof Node\Stmt\PropertyProperty || $node instanceof Node\Const_) {
             // Properties and constants can have multiple declarations
@@ -70,7 +70,7 @@ class DefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return string|null
      */
-    public function getDocumentationFromNode(Node $node)
+    public function getDocumentationFromNode($node)
     {
         if ($node instanceof Node\Stmt\PropertyProperty || $node instanceof Node\Const_) {
             $node = $node->getAttribute('parentNode');
@@ -101,7 +101,7 @@ class DefinitionResolver implements DefinitionResolverInterface
      * @param string $fqn
      * @return Definition
      */
-    public function createDefinitionFromNode(Node $node, string $fqn = null): Definition
+    public function createDefinitionFromNode($node, string $fqn = null): Definition
     {
         $parent = $node->getAttribute('parentNode');
         $def = new Definition;
@@ -141,7 +141,7 @@ class DefinitionResolver implements DefinitionResolverInterface
      * @param Node $node Any reference node
      * @return Definition|null
      */
-    public function resolveReferenceNodeToDefinition(Node $node)
+    public function resolveReferenceNodeToDefinition($node)
     {
         // Variables are not indexed globally, as they stay in the file scope anyway
         if ($node instanceof Node\Expr\Variable) {
@@ -177,7 +177,7 @@ class DefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return string|null
      */
-    public function resolveReferenceNodeToFqn(Node $node)
+    public function resolveReferenceNodeToFqn($node)
     {
         $parent = $node->getAttribute('parentNode');
 
@@ -393,7 +393,7 @@ class DefinitionResolver implements DefinitionResolverInterface
      * @param \PhpParser\Node\Expr $expr
      * @return \phpDocumentor\Reflection\Type
      */
-    public function resolveExpressionNodeToType(Node\Expr $expr): Type
+    public function resolveExpressionNodeToType($expr): Type
     {
         if ($expr instanceof Node\Expr\Variable || $expr instanceof Node\Expr\ClosureUse) {
             if ($expr instanceof Node\Expr\Variable && $expr->name === 'this') {
@@ -691,7 +691,7 @@ class DefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return \phpDocumentor\Reflection\Type|null
      */
-    public function getTypeFromNode(Node $node)
+    public function getTypeFromNode($node)
     {
         if ($node instanceof Node\Param) {
             // Parameters
@@ -798,7 +798,7 @@ class DefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return string|null
      */
-    public static function getDefinedFqn(Node $node)
+    public static function getDefinedFqn($node)
     {
         $parent = $node->getAttribute('parentNode');
         // Anonymous classes don't count as a definition
diff --git a/src/DefinitionResolverInterface.php b/src/DefinitionResolverInterface.php
index dba4935..767f4e0 100644
--- a/src/DefinitionResolverInterface.php
+++ b/src/DefinitionResolverInterface.php
@@ -4,59 +4,60 @@ namespace LanguageServer;
 
 use phpDocumentor\Reflection\Type;
 use PhpParser\Node;
+use Microsoft\PhpParser as Tolerant;
 
 interface DefinitionResolverInterface
 {
     /**
      * Builds the declaration line for a given node
      *
-     * @param Node $node
+     * @param Node | Tolerant\Node $node
      * @return string
      */
-    public function getDeclarationLineFromNode(Node $node) : string;
+    public function getDeclarationLineFromNode($node) : string;
 
     /**
      * Gets the documentation string for a node, if it has one
      *
-     * @param Node $node
+     * @param Node | Tolerant\Node $node
      * @return string|null
      */
-    public function getDocumentationFromNode(Node $node);
+    public function getDocumentationFromNode($node);
 
     /**
      * Create a Definition for a definition node
      *
-     * @param Node $node
+     * @param Node | Tolerant\Node $node
      * @param string $fqn
      * @return Definition
      */
-    public function createDefinitionFromNode(Node $node, string $fqn = null) : Definition;
+    public function createDefinitionFromNode($node, string $fqn = null) : Definition;
 
     /**
      * Given any node, returns the Definition object of the symbol that is referenced
      *
-     * @param Node $node Any reference node
+     * @param Node | Tolerant\Node $node Any reference node
      * @return Definition|null
      */
-    public function resolveReferenceNodeToDefinition(Node $node);
+    public function resolveReferenceNodeToDefinition($node);
 
     /**
      * Given any node, returns the FQN of the symbol that is referenced
      * Returns null if the FQN could not be resolved or the reference node references a variable
      *
-     * @param Node $node
+     * @param Node | Tolerant\Node $node
      * @return string|null
      */
-    public function resolveReferenceNodeToFqn(Node $node);
+    public function resolveReferenceNodeToFqn($node);
 
     /**
      * Given an expression node, resolves that expression recursively to a type.
      * If the type could not be resolved, returns Types\Mixed.
      *
-     * @param \PhpParser\Node\Expr $expr
+     * @param \PhpParser\Node\Expr | Tolerant\Node $expr
      * @return \phpDocumentor\Reflection\Type
      */
-    public function resolveExpressionNodeToType(Node\Expr $expr) : Type;
+    public function resolveExpressionNodeToType($expr) : Type;
 
     /**
      * Returns the type a reference to this symbol will resolve to.
@@ -69,8 +70,17 @@ interface DefinitionResolverInterface
      * If it is unknown, will be Types\Mixed.
      * Returns null if the node does not have a type.
      *
-     * @param Node $node
+     * @param Node | Tolerant\Node $node
      * @return \phpDocumentor\Reflection\Type|null
      */
-    public function getTypeFromNode(Node $node);
+    public function getTypeFromNode($node);
+
+    /**
+     * Returns the fully qualified name (FQN) that is defined by a node
+     * Returns null if the node does not declare any symbol that can be referenced by an FQN
+     *
+     * @param Node | Tolerant\Node $node
+     * @return string|null
+     */
+    public static function getDefinedFqn($node);
 }
\ No newline at end of file
diff --git a/src/TolerantDefinitionResolver.php b/src/TolerantDefinitionResolver.php
index 23fd7ec..e09a6ca 100644
--- a/src/TolerantDefinitionResolver.php
+++ b/src/TolerantDefinitionResolver.php
@@ -42,7 +42,7 @@ class TolerantDefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return string
      */
-    public function getDeclarationLineFromNode(Node $node): string
+    public function getDeclarationLineFromNode($node): string
     {
         if ($node instanceof Node\Stmt\PropertyProperty || $node instanceof Node\Const_) {
             // Properties and constants can have multiple declarations
@@ -70,7 +70,7 @@ class TolerantDefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return string|null
      */
-    public function getDocumentationFromNode(Node $node)
+    public function getDocumentationFromNode($node)
     {
         if ($node instanceof Node\Stmt\PropertyProperty || $node instanceof Node\Const_) {
             $node = $node->getAttribute('parentNode');
@@ -101,7 +101,7 @@ class TolerantDefinitionResolver implements DefinitionResolverInterface
      * @param string $fqn
      * @return Definition
      */
-    public function createDefinitionFromNode(Node $node, string $fqn = null): Definition
+    public function createDefinitionFromNode($node, string $fqn = null): Definition
     {
         $parent = $node->getAttribute('parentNode');
         $def = new Definition;
@@ -141,7 +141,7 @@ class TolerantDefinitionResolver implements DefinitionResolverInterface
      * @param Node $node Any reference node
      * @return Definition|null
      */
-    public function resolveReferenceNodeToDefinition(Node $node)
+    public function resolveReferenceNodeToDefinition($node)
     {
         // Variables are not indexed globally, as they stay in the file scope anyway
         if ($node instanceof Node\Expr\Variable) {
@@ -177,7 +177,7 @@ class TolerantDefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return string|null
      */
-    public function resolveReferenceNodeToFqn(Node $node)
+    public function resolveReferenceNodeToFqn($node)
     {
         $parent = $node->getAttribute('parentNode');
 
@@ -393,7 +393,7 @@ class TolerantDefinitionResolver implements DefinitionResolverInterface
      * @param \PhpParser\Node\Expr $expr
      * @return \phpDocumentor\Reflection\Type
      */
-    public function resolveExpressionNodeToType(Node\Expr $expr): Type
+    public function resolveExpressionNodeToType($expr): Type
     {
         if ($expr instanceof Node\Expr\Variable || $expr instanceof Node\Expr\ClosureUse) {
             if ($expr instanceof Node\Expr\Variable && $expr->name === 'this') {
@@ -691,7 +691,7 @@ class TolerantDefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return \phpDocumentor\Reflection\Type|null
      */
-    public function getTypeFromNode(Node $node)
+    public function getTypeFromNode($node)
     {
         if ($node instanceof Node\Param) {
             // Parameters
@@ -798,7 +798,7 @@ class TolerantDefinitionResolver implements DefinitionResolverInterface
      * @param Node $node
      * @return string|null
      */
-    public static function getDefinedFqn(Node $node)
+    public static function getDefinedFqn($node)
     {
         $parent = $node->getAttribute('parentNode');
         // Anonymous classes don't count as a definition