diff --git a/AK/TypeCasts.h b/AK/TypeCasts.h
index 171d898d16a..44a167b8458 100644
--- a/AK/TypeCasts.h
+++ b/AK/TypeCasts.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/Assertions.h>
+#include <AK/Forward.h>
 #include <AK/Platform.h>
 #include <AK/StdLibExtras.h>
 
@@ -27,6 +28,12 @@ ALWAYS_INLINE bool is(InputType* input)
     return input && is<OutputType>(*input);
 }
 
+template<typename OutputType, typename InputType>
+ALWAYS_INLINE bool is(NonnullRefPtr<InputType> const& input)
+{
+    return is<OutputType>(*input);
+}
+
 template<typename OutputType, typename InputType>
 ALWAYS_INLINE CopyConst<InputType, OutputType>* verify_cast(InputType* input)
 {