diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 73cb141..bf17681 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -290,7 +290,10 @@
 				OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL)
 
 extern acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags);
+extern void acpi_early_init(void);
+
 #else	/* CONFIG_ACPI */
+static inline void acpi_early_init(void) { }
 
 static inline int early_acpi_boot_init(void)
 {