diff --git a/src/daemon.vala b/src/daemon.vala
index 6961836..26eb5d5 100644
--- a/src/daemon.vala
+++ b/src/daemon.vala
@@ -126,6 +126,7 @@ namespace Pamac {
 		public Timer timer;
 		public Cancellable cancellable;
 		public Curl.Easy curl;
+		private bool authorized;
 
 		public signal void emit_event (uint primary_event, uint secondary_event, string[] details);
 		public signal void emit_providers (string depend, string[] providers);
@@ -164,6 +165,7 @@ namespace Pamac {
 			create_thread_pool ();
 			cancellable = new Cancellable ();
 			curl = new Curl.Easy ();
+			authorized = false;
 		}
 
 		public void set_environment_variables (HashTable<string,string> variables) {
@@ -261,8 +263,10 @@ namespace Pamac {
 		}
 
 		private async bool check_authorization (GLib.BusName sender) {
+			if (authorized) {
+				return true;
+			}
 			SourceFunc callback = check_authorization.callback;
-			bool authorized = false;
 			try {
 				Polkit.Authority authority = Polkit.Authority.get_sync ();
 				Polkit.Subject subject = Polkit.SystemBusName.new (sender);
@@ -286,6 +290,11 @@ namespace Pamac {
 			} catch (GLib.Error e) {
 				stderr.printf ("%s\n", e.message);
 			}
+			if (!authorized) {
+				current_error = ErrorInfos () {
+					message = _("Authentication failed")
+				};
+			}
 			return authorized;
 		}
 
@@ -348,10 +357,6 @@ namespace Pamac {
 					} catch (ThreadError e) {
 						stderr.printf ("Thread Error %s\n", e.message);
 					}
-				} else {
-					current_error = ErrorInfos () {
-						message = _("Authentication failed")
-					};
 				}
 			});
 		}
@@ -372,10 +377,6 @@ namespace Pamac {
 					} catch (Error e) {
 						stderr.printf ("Error: %s\n", e.message);
 					}
-				} else {
-					current_error = ErrorInfos () {
-						message = _("Authentication failed")
-					};
 				}
 			});
 		}
@@ -2152,9 +2153,6 @@ namespace Pamac {
 						stderr.printf ("Thread Error %s\n", e.message);
 					}
 				} else {
-					current_error = ErrorInfos () {
-						message = _("Authentication failed")
-					};
 					trans_release ();
 					trans_commit_finished (false);
 				}
diff --git a/src/transaction.vala b/src/transaction.vala
index 118316c..a827456 100644
--- a/src/transaction.vala
+++ b/src/transaction.vala
@@ -263,7 +263,8 @@ namespace Pamac {
 
 		public async void run_preferences_dialog () {
 			SourceFunc callback = run_preferences_dialog.callback;
-			ulong handler_id = daemon.get_authorization_finished.connect ((authorized) => {
+			check_authorization.begin ((obj, res) => {
+				bool authorized = check_authorization.end (res);
 				if (authorized) {
 					var preferences_dialog = new PreferencesDialog (this);
 					preferences_dialog.run ();
@@ -274,9 +275,7 @@ namespace Pamac {
 				}
 				Idle.add ((owned) callback);
 			});
-			start_get_authorization ();
 			yield;
-			daemon.disconnect (handler_id);
 		}
 
 		public void run_about_dialog () {
@@ -300,12 +299,21 @@ namespace Pamac {
 			}
 		}
 
-		void start_get_authorization () {
+		async bool check_authorization () {
+			SourceFunc callback = check_authorization.callback;
+			bool authorized = false;
+			ulong handler_id = daemon.get_authorization_finished.connect ((authorized_) => {
+				authorized = authorized_;
+				Idle.add ((owned) callback);
+			});
 			try {
 				daemon.start_get_authorization ();
 			} catch (IOError e) {
 				stderr.printf ("IOError: %s\n", e.message);
 			}
+			yield;
+			daemon.disconnect (handler_id);
+			return authorized;
 		}
 
 		public void start_write_pamac_config (HashTable<string,Variant> new_pamac_conf) {
@@ -1634,7 +1642,15 @@ namespace Pamac {
 				if (to_build_queue.get_length () != 0) {
 					show_in_term ("");
 					clear_previous_lists ();
-					build_aur_packages.begin ();
+					check_authorization.begin ((obj, res) => {
+						bool authorized = check_authorization.end (res);
+						if (authorized) {
+							build_aur_packages.begin ();
+						} else {
+							to_build_queue.clear ();
+							on_trans_commit_finished (false);
+						}
+					});
 				} else {
 					clear_previous_lists ();
 					if (sysupgrade_after_trans) {
@@ -1667,6 +1683,7 @@ namespace Pamac {
 					to_load.remove_all ();
 				}
 				clear_previous_lists ();
+				to_build_queue.clear ();
 				warning_textbuffer = new StringBuilder ();
 				handle_error (err);
 			}