diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index b32df49a3bd5..1d356105f25a 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -379,7 +379,7 @@ extern int of_setup_earlycon(const struct earlycon_id *match,
 extern bool earlycon_acpi_spcr_enable __initdata;
 int setup_earlycon(char *buf);
 #else
-static const bool earlycon_acpi_spcr_enable;
+static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED;
 static inline int setup_earlycon(char *buf) { return 0; }
 #endif