diff --git a/Userland/Libraries/LibJS/Runtime/FunctionKind.h b/Userland/Libraries/LibJS/Runtime/FunctionKind.h
index 62edbb317b..6572a7484b 100644
--- a/Userland/Libraries/LibJS/Runtime/FunctionKind.h
+++ b/Userland/Libraries/LibJS/Runtime/FunctionKind.h
@@ -6,6 +6,8 @@
 
 #pragma once
 
+#include <AK/Types.h>
+
 namespace JS {
 
 enum class FunctionKind : u8 {