diff --git a/.swiftformat b/.swiftformat
index ce62d1c..f727bd2 100644
--- a/.swiftformat
+++ b/.swiftformat
@@ -11,6 +11,7 @@
 --disable blankLinesAroundMark
 --disable consecutiveSpaces
 --disable hoistPatternLet
+--disable hoistTry
 --disable indent
 --disable trailingCommas
 
diff --git a/Sources/MasKit/AppStore/ISStoreAccount.swift b/Sources/MasKit/AppStore/ISStoreAccount.swift
index 29be002..ae62f10 100644
--- a/Sources/MasKit/AppStore/ISStoreAccount.swift
+++ b/Sources/MasKit/AppStore/ISStoreAccount.swift
@@ -7,85 +7,81 @@
 //
 
 import CommerceKit
+import PromiseKit
 import StoreFoundation
 
 extension ISStoreAccount: StoreAccount {
-    static var primaryAccount: ISStoreAccount? {
+    static var primaryAccount: Promise<ISStoreAccount> {
         if #available(macOS 10.13, *) {
-            let group = DispatchGroup()
-            group.enter()
-
-            var account: ISStoreAccount?
-            ISServiceProxy.genericShared().accountService.primaryAccount { storeAccount in
-                account = storeAccount
-                group.leave()
-            }
-
-            _ = group.wait(timeout: .now() + 30)
-
-            return account
+            return race(
+                Promise<ISStoreAccount> { seal in
+                    ISServiceProxy.genericShared().accountService.primaryAccount { storeAccount in
+                        seal.fulfill(storeAccount)
+                    }
+                },
+                after(seconds: 30).then {
+                    Promise(error: MASError.notSignedIn)
+                }
+            )
         } else {
-            return CKAccountStore.shared().primaryAccount
+            return .value(CKAccountStore.shared().primaryAccount)
         }
     }
 
-    static func signIn(username: String, password: String, systemDialog: Bool = false) throws -> ISStoreAccount {
+    static func signIn(username: String, password: String, systemDialog: Bool) -> Promise<ISStoreAccount> {
         if #available(macOS 10.13, *) {
             // Signing in is no longer possible as of High Sierra.
             // https://github.com/mas-cli/mas/issues/164
-            throw MASError.notSupported
+            return Promise(error: MASError.notSupported)
         } else {
-            if let account = primaryAccount, account.isSignedIn {
-                throw MASError.alreadySignedIn(asAccountId: account.identifier)
-            }
+            return
+                primaryAccount
+                .then { account -> Promise<ISStoreAccount> in
+                    if account.isSignedIn {
+                        return Promise(error: MASError.alreadySignedIn(asAccountId: account.identifier))
+                    }
 
-            let password =
-                password.isEmpty && !systemDialog
-                ? String(validatingUTF8: getpass("Password: "))!
-                : password
+                    let password =
+                        password.isEmpty && !systemDialog
+                        ? String(validatingUTF8: getpass("Password: "))!
+                        : password
 
-            guard !password.isEmpty || systemDialog else {
-                throw MASError.noPasswordProvided
-            }
+                    guard !password.isEmpty || systemDialog else {
+                        return Promise(error: MASError.noPasswordProvided)
+                    }
 
-            let accountService = ISServiceProxy.genericShared().accountService
-            accountService.setStoreClient(ISStoreClient(storeClientType: 0))
+                    let context = ISAuthenticationContext(accountID: 0)
+                    context.appleIDOverride = username
 
-            let context = ISAuthenticationContext(accountID: 0)
-            context.appleIDOverride = username
-            if !systemDialog {
-                context.demoMode = true
-                context.demoAccountName = username
-                context.demoAccountPassword = password
-                context.demoAutologinMode = true
-            }
+                    let signInPromise =
+                        Promise<ISStoreAccount> { seal in
+                            let accountService = ISServiceProxy.genericShared().accountService
+                            accountService.setStoreClient(ISStoreClient(storeClientType: 0))
+                            accountService.signIn(with: context) { success, storeAccount, error in
+                                if success, let storeAccount {
+                                    seal.fulfill(storeAccount)
+                                } else {
+                                    seal.reject(MASError.signInFailed(error: error as NSError?))
+                                }
+                            }
+                        }
 
-            let group = DispatchGroup()
-            group.enter()
+                    if systemDialog {
+                        return signInPromise
+                    } else {
+                        context.demoMode = true
+                        context.demoAccountName = username
+                        context.demoAccountPassword = password
+                        context.demoAutologinMode = true
 
-            var storeAccount: ISStoreAccount?
-            var maserror: MASError?
-            // Only works on macOS Sierra and below
-            accountService.signIn(with: context) { success, account, error in
-                if success, let account {
-                    storeAccount = account
-                } else {
-                    maserror = .signInFailed(error: error as NSError?)
+                        return race(
+                            signInPromise,
+                            after(seconds: 30).then {
+                                Promise(error: MASError.signInFailed(error: nil))
+                            }
+                        )
+                    }
                 }
-                group.leave()
-            }
-
-            if systemDialog {
-                group.wait()
-            } else {
-                _ = group.wait(timeout: .now() + 30)
-            }
-
-            if let storeAccount {
-                return storeAccount
-            }
-
-            throw maserror ?? MASError.signInFailed(error: nil)
         }
     }
 }
diff --git a/Sources/MasKit/AppStore/SSPurchase.swift b/Sources/MasKit/AppStore/SSPurchase.swift
index 5fd0eab..2bab990 100644
--- a/Sources/MasKit/AppStore/SSPurchase.swift
+++ b/Sources/MasKit/AppStore/SSPurchase.swift
@@ -45,7 +45,7 @@ extension SSPurchase {
             // Monterey obscures the user's App Store account information, but allows
             // redownloads without passing the account to SSPurchase.
             // https://github.com/mas-cli/mas/issues/417
-            if let storeAccount = ISStoreAccount.primaryAccount {
+            if let storeAccount = try? ISStoreAccount.primaryAccount.wait() {
                 accountIdentifier = storeAccount.dsID
                 appleID = storeAccount.identifier
             }
diff --git a/Sources/MasKit/Commands/Account.swift b/Sources/MasKit/Commands/Account.swift
index 9701054..333e2d2 100644
--- a/Sources/MasKit/Commands/Account.swift
+++ b/Sources/MasKit/Commands/Account.swift
@@ -24,11 +24,11 @@ public struct AccountCommand: CommandProtocol {
             return .failure(.notSupported)
         }
 
-        if let account = ISStoreAccount.primaryAccount {
-            print(account.identifier)
-        } else {
-            return .failure(.notSignedIn)
+        do {
+            print(try ISStoreAccount.primaryAccount.wait().identifier)
+            return .success(())
+        } catch {
+            return .failure(error as? MASError ?? .failed(error: error as NSError))
         }
-        return .success(())
     }
 }
diff --git a/Sources/MasKit/Commands/SignIn.swift b/Sources/MasKit/Commands/SignIn.swift
index 1ac241f..e04769e 100644
--- a/Sources/MasKit/Commands/SignIn.swift
+++ b/Sources/MasKit/Commands/SignIn.swift
@@ -25,6 +25,7 @@ public struct SignInCommand: CommandProtocol {
                 password: options.password,
                 systemDialog: options.dialog
             )
+            .wait()
             return .success(())
         } catch {
             return .failure(error as? MASError ?? .signInFailed(error: error as NSError))
diff --git a/Sources/MasKit/Errors/MASError.swift b/Sources/MasKit/Errors/MASError.swift
index 57e40af..d5c4683 100644
--- a/Sources/MasKit/Errors/MASError.swift
+++ b/Sources/MasKit/Errors/MASError.swift
@@ -11,6 +11,8 @@ import Foundation
 public enum MASError: Error, Equatable {
     case notSupported
 
+    case failed(error: NSError?)
+
     case notSignedIn
     case noPasswordProvided
     case signInFailed(error: NSError?)
@@ -46,6 +48,12 @@ extension MASError: CustomStringConvertible {
                 For more information see: \
                 https://github.com/mas-cli/mas#%EF%B8%8F-known-issues
                 """
+        case .failed(let error):
+            if let error {
+                return "Failed: \(error.localizedDescription)"
+            } else {
+                return "Failed"
+            }
         case .signInFailed(let error):
             if let error {
                 return "Sign in failed: \(error.localizedDescription)"