diff --git a/resources/qml/PrintMonitor.qml b/resources/qml/PrintMonitor.qml
index bead30d85b..6e9eafaf78 100644
--- a/resources/qml/PrintMonitor.qml
+++ b/resources/qml/PrintMonitor.qml
@@ -318,7 +318,7 @@ Column
             height: UM.Theme.getSize("setting_control").height
             enabled:
             {
-                if (!connectedPrinter != null)
+                if (connectedPrinter == null)
                 {
                     return false; //Can't preheat if not connected.
                 }