diff --git a/Sources/PerfectCrypto/Extensions.swift b/Sources/PerfectCrypto/Extensions.swift
index 552fc1e..5e005ab 100644
--- a/Sources/PerfectCrypto/Extensions.swift
+++ b/Sources/PerfectCrypto/Extensions.swift
@@ -69,8 +69,8 @@ public extension File {
 		try chain.flush()
 		let validLength = digest.length
 		let ret = UnsafeMutableRawBufferPointer.allocate(byteCount: validLength, alignment: 0)
+		defer { ret.deallocate() }
 		guard try filter.get(ret) == validLength else {
-			ret.deallocate()
 			return []
 		}
 		return ret.map { $0 }