diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c410be738ae7..6a190c7f4d71 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -742,7 +742,7 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
 	return 0;
 }
 
-static char *prepare_command_line(void)
+static char * __init prepare_command_line(void)
 {
 #ifdef CONFIG_CMDLINE_BOOL
 #ifdef CONFIG_CMDLINE_OVERRIDE