diff --git a/radio/src/gui/colorlcd/layouts/topbar_impl.cpp b/radio/src/gui/colorlcd/layouts/topbar_impl.cpp
index 89068e728..4ab4641fb 100644
--- a/radio/src/gui/colorlcd/layouts/topbar_impl.cpp
+++ b/radio/src/gui/colorlcd/layouts/topbar_impl.cpp
@@ -34,7 +34,7 @@ TopbarImpl::TopbarImpl(Window * parent) :
 unsigned int TopbarImpl::getZonesCount() const
 {
 #if defined(INTERNAL_GPS)
-  if (hasSerialMode(UART_MODE_GPS)) {
+  if (hasSerialMode(UART_MODE_GPS) != -1) {
     return MAX_TOPBAR_ZONES-1;
   }
 #endif