diff --git a/Firmware/mmu2_marlin_macros.h b/Firmware/mmu2_marlin_macros.h
index af2f79504..38f515e66 100644
--- a/Firmware/mmu2_marlin_macros.h
+++ b/Firmware/mmu2_marlin_macros.h
@@ -8,6 +8,10 @@
     // brings _O and _T macros into MMU
     #include "language.h"
     #define MARLIN_KEEPALIVE_STATE_IN_PROCESS KEEPALIVE_STATE(IN_PROCESS)
+#elif defined(UNITTEST)
+    #define _O(x)                             x
+    #define _T(x)                             x
+    #define MARLIN_KEEPALIVE_STATE_IN_PROCESS /*KEEPALIVE_STATE(IN_PROCESS) TODO*/
 #else
     #include "../../gcode/gcode.h"
     #define _O(x)                             x