diff --git a/tests/template/parent_templates/parent_and_child.js b/tests/template/parent_templates/parent_and_child.js
new file mode 100644
index 0000000000..6d9bb163bf
--- /dev/null
+++ b/tests/template/parent_templates/parent_and_child.js
@@ -0,0 +1 @@
+// JavaScript file in a parent style.
diff --git a/tests/template/parent_templates/parent_only.js b/tests/template/parent_templates/parent_only.js
new file mode 100644
index 0000000000..9c3007d83f
--- /dev/null
+++ b/tests/template/parent_templates/parent_only.js
@@ -0,0 +1 @@
+// JavaScript file only in parent style.
diff --git a/tests/template/template_includejs_test.php b/tests/template/template_includejs_test.php
index d80254072b..a8f9a9037f 100644
--- a/tests/template/template_includejs_test.php
+++ b/tests/template/template_includejs_test.php
@@ -18,13 +18,13 @@ class phpbb_template_template_includejs_test extends phpbb_template_template_tes
 
 		// Prepare correct result
 		$scripts = array(
-			'<script src="' . $this->test_path . '/templates/parent_and_child.html?assets_version=1"></script>',
-			'<script src="' . $this->test_path . '/parent_templates/parent_only.html?assets_version=1"></script>',
-			'<script src="' . $this->test_path . '/templates/child_only.html?assets_version=1"></script>'
+			'<script src="' . $this->test_path . '/templates/parent_and_child.js?assets_version=1"></script>',
+			'<script src="' . $this->test_path . '/parent_templates/parent_only.js?assets_version=1"></script>',
+			'<script src="' . $this->test_path . '/templates/child_only.js?assets_version=1"></script>'
 		);
 
 		// Run test
 		$cache_file = $this->template->cachepath . 'includejs.html.php';
-		$this->run_template('includejs.html', array('PARENT' => 'parent_only.html'), array(), array(), implode('', $scripts), $cache_file);
+		$this->run_template('includejs.html', array('PARENT' => 'parent_only.js'), array(), array(), implode('', $scripts), $cache_file);
 	}
 }
diff --git a/tests/template/templates/child_only.js b/tests/template/templates/child_only.js
new file mode 100644
index 0000000000..542b26526c
--- /dev/null
+++ b/tests/template/templates/child_only.js
@@ -0,0 +1 @@
+// JavaScript file only in a child style.
diff --git a/tests/template/templates/includejs.html b/tests/template/templates/includejs.html
index 186fc30b43..8a2587d76b 100644
--- a/tests/template/templates/includejs.html
+++ b/tests/template/templates/includejs.html
@@ -1,5 +1,5 @@
-<!-- INCLUDEJS parent_and_child.html -->
+<!-- INCLUDEJS parent_and_child.js -->
 <!-- INCLUDEJS {PARENT} -->
-<!-- DEFINE $TEST = 'child_only.html' -->
+<!-- DEFINE $TEST = 'child_only.js' -->
 <!-- INCLUDEJS {$TEST} -->
 {SCRIPTS}
\ No newline at end of file
diff --git a/tests/template/templates/parent_and_child.js b/tests/template/templates/parent_and_child.js
new file mode 100644
index 0000000000..d544d94d83
--- /dev/null
+++ b/tests/template/templates/parent_and_child.js
@@ -0,0 +1 @@
+// JavaScript file in a child style.