diff --git a/tests/Index/IndexTest.php b/tests/Index/IndexTest.php
new file mode 100644
index 0000000..8236f8d
--- /dev/null
+++ b/tests/Index/IndexTest.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace LanguageServer\Tests;
+
+use PHPUnit\Framework\TestCase;
+use LanguageServer\Index\Index;
+use LanguageServer\Definition;
+
+class IndexTest extends TestCase
+{
+    public function testGetSetMethodDefinition()
+    {
+        $index = new Index;
+        $index->setDefinition('SomeNamespace\SomeClass', new Definition);
+        $methodDefinition = new Definition;
+        $methodFqn = 'SomeNamespace\SomeClass->someMethod()';
+        $index->setDefinition($methodFqn, $methodDefinition);
+        $index->setDefinition('SomeNamespace\SomeClass->someProperty', new Definition);
+        $this->assertSame($methodDefinition, $index->getDefinition($methodFqn));
+    }
+
+    public function testGetSetClassDefinition()
+    {
+        $index = new Index;
+        $definition = new Definition;
+        $fqn = 'SomeNamespace\SomeClass';
+        $index->setDefinition($fqn, $definition);
+        $this->assertSame($definition, $index->getDefinition($fqn));
+    }
+}