diff --git a/syncplay/resources/lock_green_dialog@2x.png b/syncplay/resources/lock_green_dialog@2x.png
new file mode 100644
index 0000000..44788f1
Binary files /dev/null and b/syncplay/resources/lock_green_dialog@2x.png differ
diff --git a/syncplay/ui/gui.py b/syncplay/ui/gui.py
index de2f6bb..d239507 100755
--- a/syncplay/ui/gui.py
+++ b/syncplay/ui/gui.py
@@ -207,9 +207,10 @@ class CertificateDialog(QtWidgets.QDialog):
             descLabel.setFont(QtGui.QFont("Helvetica", 12))
             connDataLabel.setFont(QtGui.QFont("Helvetica", 12))
             certDataLabel.setFont(QtGui.QFont("Helvetica", 12))
-        lockIconPixmap = QtGui.QPixmap(resourcespath + "lock_green_dialog.png")
+        lockIcon = QtGui.QIcon()
+        lockIcon.addFile(resourcespath + "lock_green_dialog.png")
         lockIconLabel = QtWidgets.QLabel()
-        lockIconLabel.setPixmap(lockIconPixmap.scaled(64, 64, Qt.KeepAspectRatio))
+        lockIconLabel.setPixmap(lockIcon.pixmap(64, 64))
         certLayout = QtWidgets.QGridLayout()
         certLayout.addWidget(lockIconLabel, 1, 0, 3, 1, Qt.AlignLeft | Qt.AlignTop)
         certLayout.addWidget(statusLabel, 0, 1, 1, 3)