diff --git a/src/Psalm/Checker/FunctionLikeChecker.php b/src/Psalm/Checker/FunctionLikeChecker.php
index 4f812d4ab..706792fef 100644
--- a/src/Psalm/Checker/FunctionLikeChecker.php
+++ b/src/Psalm/Checker/FunctionLikeChecker.php
@@ -314,7 +314,13 @@ abstract class FunctionLikeChecker extends SourceChecker implements StatementsSo
     public function getMethodId()
     {
         if ($this->function instanceof ClassMethod) {
-            return $this->fq_class_name . '::' . strtolower($this->function->name);
+            $function_name = $this->function->name;
+
+            if (strtolower($function_name) === strtolower($this->class_name)) {
+                $function_name = '__construct';
+            }
+
+            return $this->fq_class_name . '::' . strtolower($function_name);
         }
 
         if ($this->function instanceof Function_) {
diff --git a/src/Psalm/Checker/MethodChecker.php b/src/Psalm/Checker/MethodChecker.php
index 97055a261..5b22868ba 100644
--- a/src/Psalm/Checker/MethodChecker.php
+++ b/src/Psalm/Checker/MethodChecker.php
@@ -172,8 +172,14 @@ class MethodChecker extends FunctionLikeChecker
      */
     public static function extractReflectionMethodInfo(\ReflectionMethod $method)
     {
-        $method_id = $method->class . '::' . strtolower((string)$method->name);
-        self::$cased_method_ids[$method_id] = $method->class . '::' . $method->name;
+        if (strtolower($method->name) === strtolower((string)$method->class)) {
+            $method_id = $method->class . '::__construct';
+            self::$cased_method_ids[$method_id] = $method->class . '::__construct';
+        }
+        else {
+            $method_id = $method->class . '::' . strtolower($method->name);
+            self::$cased_method_ids[$method_id] = $method->class . '::' . $method->name;
+        }
 
         if (isset(self::$have_reflected[$method_id])) {
             return null;
@@ -255,7 +261,13 @@ class MethodChecker extends FunctionLikeChecker
      */
     protected function registerMethod(PhpParser\Node\Stmt\ClassMethod $method)
     {
-        $method_id = $this->fq_class_name . '::' . strtolower($method->name);
+        if (strtolower($method->name) === strtolower((string)$this->class_name)) {
+            $method_id = $this->fq_class_name . '::__construct';
+        }
+        else {
+            $method_id = $this->fq_class_name . '::' . strtolower($method->name);
+        }
+
         $cased_method_id = self::$cased_method_ids[$method_id] = $this->fq_class_name . '::' . $method->name;
 
         if (isset(self::$have_reflected[$method_id]) || isset(self::$have_registered[$method_id])) {
@@ -459,15 +471,19 @@ class MethodChecker extends FunctionLikeChecker
 
         self::registerClassMethod($method_id);
 
+        $old_method_id = null;
+
         if (isset(self::$declaring_methods[$method_id])) {
             return true;
         }
 
+        // support checking oldstyle constructors
         if ($method_parts[1] === '__construct') {
-            // @todo ?
+            $old_constructor_name = array_pop(explode('\\', $method_parts[0]));
+            $old_method_id = $method_parts[0] . '::' . $old_constructor_name;
         }
 
-        if (FunctionChecker::inCallMap($method_id)) {
+        if (FunctionChecker::inCallMap($method_id) || ($old_method_id && FunctionChecker::inCallMap($method_id))) {
             return true;
         }
 
diff --git a/tests/Php40Test.php b/tests/Php40Test.php
new file mode 100644
index 000000000..6fba8687d
--- /dev/null
+++ b/tests/Php40Test.php
@@ -0,0 +1,48 @@
+<?php
+namespace Psalm\Tests;
+
+use PhpParser\ParserFactory;
+use PHPUnit_Framework_TestCase;
+use Psalm\Checker\FileChecker;
+use Psalm\Config;
+use Psalm\Context;
+
+class Php40Test extends PHPUnit_Framework_TestCase
+{
+    protected static $parser;
+
+    public static function setUpBeforeClass()
+    {
+        self::$parser = (new ParserFactory)->create(ParserFactory::PREFER_PHP7);
+
+        $config = Config::getInstance();
+        $config->throw_exception = true;
+        $config->use_docblock_types = true;
+    }
+
+    public function setUp()
+    {
+        FileChecker::clearCache();
+    }
+
+    public function testExtendOldStyleConstructor()
+    {
+        $stmts = self::$parser->parse('<?php
+        class A {
+            public function A() {
+
+            }
+        }
+
+        class B extends A {
+            public function __construct() {
+                parent::__construct();
+            }
+        }
+        ');
+
+        $file_checker = new FileChecker('somefile.php', $stmts);
+        $context = new Context('somefile.php');
+        $file_checker->check(true, true, $context);
+    }
+}