diff --git a/SignalMetadataKit/src/SMKUDAccessKey.swift b/SignalMetadataKit/src/SMKUDAccessKey.swift
index d124341..71aa6e9 100644
--- a/SignalMetadataKit/src/SMKUDAccessKey.swift
+++ b/SignalMetadataKit/src/SMKUDAccessKey.swift
@@ -23,7 +23,7 @@ public class SMKUDAccessKey: NSObject {
         // We derive the "ud access key" from the private key by encrypting zeroes.
         let emptyPlaintextLength = 16
         let emptyPlaintext = Data(count: Int(emptyPlaintextLength))
-        let initializationVector = Data(count: Int(kAESGCM256_IVLength))
+        let initializationVector = Data(count: Int(kAESGCM256_DefaultIVLength))
         guard let keyData = Cryptography.encryptAESGCM(plainTextData: emptyPlaintext,
                                                 initializationVector: initializationVector,
                                                 additionalAuthenticatedData: nil,