diff --git a/SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI+Encryption.swift b/SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI+Encryption.swift
index 35af7a475..1fc7d232f 100644
--- a/SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI+Encryption.swift	
+++ b/SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI+Encryption.swift	
@@ -2,7 +2,7 @@ import CryptoSwift
 import PromiseKit
 
 extension OnionRequestAPI {
-    internal static let gcmTagLength: UInt = 128
+    internal static let gcmTagSize: UInt = 16
     internal static let ivSize: UInt = 12
 
     internal typealias EncryptionResult = (ciphertext: Data, symmetricKey: Data, ephemeralPublicKey: Data)
@@ -24,7 +24,7 @@ extension OnionRequestAPI {
     private static func encrypt(_ plaintext: Data, usingAESGCMWithSymmetricKey symmetricKey: Data) throws -> Data {
         guard !Thread.isMainThread else { preconditionFailure("It's illegal to call encrypt(_:usingAESGCMWithSymmetricKey:) from the main thread.") }
         let iv = try getSecureRandomData(ofSize: ivSize)
-        let gcm = GCM(iv: iv.bytes, tagLength: Int(gcmTagLength), mode: .combined)
+        let gcm = GCM(iv: iv.bytes, tagLength: Int(gcmTagSize), mode: .combined)
         let aes = try AES(key: symmetricKey.bytes, blockMode: gcm, padding: .pkcs7)
         let ciphertext = try aes.encrypt(plaintext.bytes)
         return iv + Data(bytes: ciphertext)
diff --git a/SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI.swift b/SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI.swift
index 2248cc37a..e7da970ac 100644
--- a/SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI.swift	
+++ b/SignalServiceKit/src/Loki/API/Onion Requests/OnionRequestAPI.swift	
@@ -272,12 +272,12 @@ internal enum OnionRequestAPI {
                     guard let json = rawResponse as? JSON, let base64EncodedIVAndCiphertext = json["result"] as? String,
                         let ivAndCiphertext = Data(base64Encoded: base64EncodedIVAndCiphertext) else { return seal.reject(Error.invalidJSON) }
                     let iv = ivAndCiphertext[0..<Int(ivSize)]
-                    let ciphertext = ivAndCiphertext[Int(ivSize)..<ivAndCiphertext.endIndex]
+                    let ciphertext = ivAndCiphertext[Int(ivSize)...]
                     do {
-                        let gcm = GCM(iv: iv.bytes, tagLength: Int(gcmTagLength), mode: .combined)
+                        let gcm = GCM(iv: iv.bytes, tagLength: Int(gcmTagSize), mode: .combined)
                         let aes = try AES(key: symmetricKey.bytes, blockMode: gcm, padding: .pkcs7)
                         let result = try aes.decrypt(ciphertext.bytes)
-                        seal.fulfill(result)
+                        seal.fulfill(Data(bytes: result))
                     } catch (let error) {
                         seal.reject(error)
                     }