diff --git a/arch/arm/src/armv7-a/smp.h b/arch/arm/src/armv7-a/smp.h
index 15071254f28..865c847b30d 100644
--- a/arch/arm/src/armv7-a/smp.h
+++ b/arch/arm/src/armv7-a/smp.h
@@ -84,6 +84,8 @@ extern uint32_t g_cpu3_idlestack[SMP_STACK_WORDS];
  *
  ****************************************************************************/
 
+void __start(void);
+
 #if CONFIG_SMP_NCPUS > 1
 void __cpu1_start(void);
 #endif
diff --git a/arch/arm/src/armv7-r/smp.h b/arch/arm/src/armv7-r/smp.h
index 2058eeaf3b6..4edc49ee344 100644
--- a/arch/arm/src/armv7-r/smp.h
+++ b/arch/arm/src/armv7-r/smp.h
@@ -84,6 +84,8 @@ extern uint32_t g_cpu3_idlestack[SMP_STACK_WORDS];
  *
  ****************************************************************************/
 
+void __start(void);
+
 #if CONFIG_SMP_NCPUS > 1
 void __cpu1_start(void);
 #endif