Ending a sentence with a preposition is grammatically wrong; you must rephrase to move the preposition earlier in the sentence.
Like the split infinitive rule, the preposition-at-the-end prohibition is based on false Latin analogy. Latin cannot easily end sentences with prepositions due to its case system, so when prescriptive grammarians applied this to English in the 18th-19th centuries, they created an artificial rule. English allows and naturally uses sentence-final prepositions: 'What are you talking about?' 'This is the house I grew up in.' 'Where did you get that from?' Sound linguistic principle and all major style guides support final prepositions. Winston Churchill's quip about the rule ('a preposition is something up with which I will not put') humorously illustrates how forced adherence produces unnatural prose.