diff --git a/client/core/servercontroller.cpp b/client/core/servercontroller.cpp
index a0df4dc0..2a83c2d8 100644
--- a/client/core/servercontroller.cpp
+++ b/client/core/servercontroller.cpp
@@ -539,7 +539,7 @@ ErrorCode ServerController::installDockerWorker(const ServerCredentials &credent
     QFutureWatcher<ErrorCode> watcher;
 
     QFuture<ErrorCode> future = QtConcurrent::run([this, &stdOut, &cbReadStdOut, &cbReadStdErr, &credentials]() {
-        do {
+        while (true) {
             if (m_cancelInstallation) {
                 return ErrorCode::ServerCancelInstallation;
             }
@@ -547,12 +547,13 @@ ErrorCode ServerController::installDockerWorker(const ServerCredentials &credent
             runScript(credentials,
                       replaceVars(amnezia::scriptData(SharedScriptType::check_server_is_busy),
                                   genVarsForScript(credentials)), cbReadStdOut, cbReadStdErr);
-            if (!stdOut.isEmpty() || stdOut.contains("Unable to acquire the dpkg frontend lock")) {
+            if (stdOut.contains("/var/lib/dpkg/lock-frontend")) {
                 emit serverIsBusy(true);
                 QThread::msleep(1000);
+            } else {
+                return ErrorCode::NoError;
             }
-        } while (!stdOut.isEmpty());
-        return ErrorCode::NoError;
+        }
     });
 
     QEventLoop wait;
diff --git a/client/defines.h b/client/defines.h
index c64eb458..d13b1050 100644
--- a/client/defines.h
+++ b/client/defines.h
@@ -4,7 +4,7 @@
 #define APPLICATION_NAME    "AmneziaVPN"
 #define SERVICE_NAME        "AmneziaVPN-service"
 #define ORGANIZATION_NAME   "AmneziaVPN.ORG"
-#define APP_MAJOR_VERSION   "2.1.2"
-#define APP_VERSION         "2.1.2.0"
+#define APP_MAJOR_VERSION   "2.1.3"
+#define APP_VERSION         "2.1.3.0"
 
 #endif // DEFINES_H
diff --git a/client/server_scripts/check_server_is_busy.sh b/client/server_scripts/check_server_is_busy.sh
index 17c27864..72f267ec 100644
--- a/client/server_scripts/check_server_is_busy.sh
+++ b/client/server_scripts/check_server_is_busy.sh
@@ -1,4 +1,4 @@
 pm_apt="/usr/bin/apt-get";\
 if [[ -f "$pm_apt" ]]; then pm=$pm_apt; else exit; fi;\
 if [[ ! -f "/usr/bin/sudo" ]]; then $pm update -y -q; $pm install -y -q sudo; fi;\
-sudo fuser /var/lib/dpkg/lock-frontend
\ No newline at end of file
+sudo lsof /var/lib/dpkg/lock-frontend
\ No newline at end of file