diff -Naur nv.orig/conftest.sh nv/conftest.sh
--- nv.orig/conftest.sh	2015-01-02 18:00:55.768624000 +0100
+++ nv/conftest.sh	2015-01-02 18:01:36.289567499 +0100
@@ -943,7 +943,7 @@
             # and how many arguments it takes.
             #
             echo "$CONFTEST_PREAMBLE
-            #include <acpi/acpi.h>
+            #include <linux/acpi.h>
             void conftest_acpi_walk_namespace(void) {
                 acpi_walk_namespace();
             }" > conftest$$.c
@@ -958,7 +958,7 @@
             fi
 
             echo "$CONFTEST_PREAMBLE
-            #include <acpi/acpi.h>
+            #include <linux/acpi.h>
             void conftest_acpi_walk_namespace(void) {
                 acpi_walk_namespace(0, NULL, 0, NULL, NULL, NULL, NULL);
             }" > conftest$$.c
@@ -974,7 +974,7 @@
             fi
 
             echo "$CONFTEST_PREAMBLE
-            #include <acpi/acpi.h>
+            #include <linux/acpi.h>
             void conftest_acpi_walk_namespace(void) {
                 acpi_walk_namespace(0, NULL, 0, NULL, NULL, NULL);
             }" > conftest$$.c