diff --git a/demos/ATSAMA5D2/RT-SAMA5D2-XPLAINED-SEC/Makefile b/demos/ATSAMA5D2/RT-SAMA5D2-XPLAINED-SEC/Makefile
index 2d41ab483..7d9752479 100755
--- a/demos/ATSAMA5D2/RT-SAMA5D2-XPLAINED-SEC/Makefile
+++ b/demos/ATSAMA5D2/RT-SAMA5D2-XPLAINED-SEC/Makefile
@@ -223,10 +223,10 @@ CPPWARN = -Wall -Wextra -Wundef
 #
 
 # List all user C define here, like -D_DEBUG=1
-UDEFS = -DCH_CFG_USE_MMU
+UDEFS =
 
 # Define ASM defines here
-UADEFS = -DCH_CFG_USE_MMU
+UADEFS =
 
 # List all user directories here
 UINCDIR =