diff --git a/include/asm-ia64/acpi-ext.h b/include/asm-ia64/acpi-ext.h
index 9271d74c64ccffc728bf3b5a2070adc4b2104a3d..56d2ddc97b30cd9c236e8b173edeea52ae2fc0c0 100644
--- a/include/asm-ia64/acpi-ext.h
+++ b/include/asm-ia64/acpi-ext.h
@@ -11,6 +11,7 @@
 #define _ASM_IA64_ACPI_EXT_H
 
 #include <linux/types.h>
+#include <acpi/actypes.h>
 
 extern acpi_status hp_acpi_csr_space (acpi_handle, u64 *base, u64 *length);