diff --git a/boot/mcuboot/Makefile b/boot/mcuboot/Makefile
index 3fca9bc27..9914fee0c 100644
--- a/boot/mcuboot/Makefile
+++ b/boot/mcuboot/Makefile
@@ -31,23 +31,27 @@ VPATH   += :$(MCUBOOT_UNPACK)$(DELIM)src
 VPATH   += :$(MCUBOOT_SRCDIR)
 
 ifneq ($(CONFIG_MCUBOOT_UPDATE_AGENT_EXAMPLE),)
-MAINSRC   = mcuboot_agent_main.c
+MAINSRC   += mcuboot_agent_main.c
 
-PROGNAME  = mcuboot_agent
-PRIORITY  = SCHED_PRIORITY_DEFAULT
-STACKSIZE = $(CONFIG_DEFAULT_TASK_STACKSIZE)
-else ifneq ($(CONFIG_MCUBOOT_SLOT_CONFIRM_EXAMPLE),)
-MAINSRC   = mcuboot_confirm_main.c
+PROGNAME  += mcuboot_agent
+PRIORITY  += SCHED_PRIORITY_DEFAULT
+STACKSIZE += $(CONFIG_DEFAULT_TASK_STACKSIZE)
+endif
 
-PROGNAME  = mcuboot_confirm
-PRIORITY  = SCHED_PRIORITY_DEFAULT
-STACKSIZE = $(CONFIG_DEFAULT_TASK_STACKSIZE)
-else ifneq ($(CONFIG_MCUBOOT_BOOTLOADER),)
-MAINSRC   = mcuboot/boot/nuttx/main.c
+ifneq ($(CONFIG_MCUBOOT_SLOT_CONFIRM_EXAMPLE),)
+MAINSRC   += mcuboot_confirm_main.c
 
-PROGNAME  = mcuboot_loader
-PRIORITY  = SCHED_PRIORITY_DEFAULT
-STACKSIZE = $(CONFIG_DEFAULT_TASK_STACKSIZE)
+PROGNAME  += mcuboot_confirm
+PRIORITY  += SCHED_PRIORITY_DEFAULT
+STACKSIZE += $(CONFIG_DEFAULT_TASK_STACKSIZE)
+endif
+
+ifneq ($(CONFIG_MCUBOOT_BOOTLOADER),)
+MAINSRC   += mcuboot/boot/nuttx/main.c
+
+PROGNAME  += mcuboot_loader
+PRIORITY  += SCHED_PRIORITY_DEFAULT
+STACKSIZE += $(CONFIG_DEFAULT_TASK_STACKSIZE)
 endif
 
 CFLAGS += -Wno-undef