diff --git a/sys/compat/linuxkpi/common/include/acpi/acpi.h b/sys/compat/linuxkpi/common/include/acpi/acpi.h
--- a/sys/compat/linuxkpi/common/include/acpi/acpi.h
+++ b/sys/compat/linuxkpi/common/include/acpi/acpi.h
@@ -46,8 +46,8 @@
 #include <contrib/dev/acpica/include/acpi.h>
 #undef BOOLEAN
 
+typedef	ACPI_IO_ADDRESS		acpi_io_address;
 typedef ACPI_HANDLE		acpi_handle;
-typedef ACPI_OBJECT		acpi_object;
 typedef ACPI_OBJECT_HANDLER	acpi_object_handler;
 typedef ACPI_OBJECT_TYPE	acpi_object_type;
 typedef ACPI_STATUS		acpi_status;
@@ -55,12 +55,56 @@
 typedef ACPI_SIZE		acpi_size;
 typedef ACPI_WALK_CALLBACK	acpi_walk_callback;
 
+union linuxkpi_acpi_object {
+	acpi_object_type type;
+	struct {
+		acpi_object_type type;
+		UINT64 value;
+	} integer;
+	struct {
+		acpi_object_type type;
+		UINT32 length;
+		char *pointer;
+	} string;
+	struct {
+		acpi_object_type type;
+		UINT32 length;
+		UINT8 *pointer;
+	} buffer;
+	struct {
+		acpi_object_type type;
+		UINT32 count;
+		union linuxkpi_acpi_object *elements;
+	} package;
+	struct {
+		acpi_object_type type;
+		acpi_object_type actual_type;
+		acpi_handle handle;
+	} reference;
+	struct {
+		acpi_object_type type;
+		UINT32 proc_id;
+		acpi_io_address pblk_address;
+		UINT32 pblk_length;
+	} processor;
+	struct {
+		acpi_object_type type;
+		UINT32 system_level;
+		UINT32 resource_order;
+	} power_resource;
+};
+
+struct linuxkpi_acpi_buffer {
+	acpi_size length;	/* Length in bytes of the buffer */
+	void *pointer;		/* pointer to buffer */
+};
+
 static inline ACPI_STATUS
 acpi_evaluate_object(ACPI_HANDLE Object, ACPI_STRING Pathname,
-    ACPI_OBJECT_LIST *ParameterObjects, ACPI_BUFFER *ReturnObjectBuffer)
+    ACPI_OBJECT_LIST *ParameterObjects, struct linuxkpi_acpi_buffer *ReturnObjectBuffer)
 {
 	return (AcpiEvaluateObject(
-	    Object, Pathname, ParameterObjects, ReturnObjectBuffer));
+	    Object, Pathname, ParameterObjects, (ACPI_BUFFER *)ReturnObjectBuffer));
 }
 
 static inline const char *
@@ -83,9 +127,9 @@
 }
 
 static inline ACPI_STATUS
-acpi_get_name(ACPI_HANDLE Object, UINT32 NameType, ACPI_BUFFER *RetPathPtr)
+acpi_get_name(ACPI_HANDLE Object, UINT32 NameType, struct linuxkpi_acpi_buffer *RetPathPtr)
 {
-	return (AcpiGetName(Object, NameType, RetPathPtr));
+	return (AcpiGetName(Object, NameType, (ACPI_BUFFER *)RetPathPtr));
 }
 
 static inline ACPI_STATUS
@@ -101,4 +145,7 @@
 	AcpiPutTable(Table);
 }
 
+#define	acpi_object		linuxkpi_acpi_object
+#define	acpi_buffer		linuxkpi_acpi_buffer
+
 #endif /* _LINUXKPI_ACPI_ACPI_H_ */