diff --git a/lib/init.lua b/lib/init.lua
index 1ab7e14..6687e66 100644
--- a/lib/init.lua
+++ b/lib/init.lua
@@ -471,7 +471,11 @@ function Promise.is(object)
 		return false
 	end
 
-	return type(object.andThen) == "function"
+	local ok, isPromise = pcall(function()
+		return type(object.andThen) == "function"
+	end)
+
+	return ok and isPromise
 end
 
 --[[