diff --git a/3rdparty/singleapplication/singleapplication_p.cpp b/3rdparty/singleapplication/singleapplication_p.cpp
index 807b6213a..9de965fa8 100644
--- a/3rdparty/singleapplication/singleapplication_p.cpp
+++ b/3rdparty/singleapplication/singleapplication_p.cpp
@@ -132,6 +132,9 @@ void SingleApplicationPrivate::genBlockServerName() {
     if (GetUserNameW(username, &usernameLength)) {
       appData.addData(QString::fromWCharArray(username).toUtf8());
     }
+    else {
+      appData.addData(qgetenv("USERNAME"));
+    }
 #endif
   }
 
diff --git a/3rdparty/singleapplication/singlecoreapplication_p.cpp b/3rdparty/singleapplication/singlecoreapplication_p.cpp
index 5d239ae56..75df19fbd 100644
--- a/3rdparty/singleapplication/singlecoreapplication_p.cpp
+++ b/3rdparty/singleapplication/singlecoreapplication_p.cpp
@@ -132,6 +132,9 @@ void SingleCoreApplicationPrivate::genBlockServerName() {
     if (GetUserNameW(username, &usernameLength)) {
       appData.addData(QString::fromWCharArray(username).toUtf8());
     }
+    else {
+      appData.addData(qgetenv("USERNAME"));
+    }
 #endif
   }