diff --git a/conftest.sh b/conftest.sh
index 6e6da83..678b79c 100755
--- a/conftest.sh
+++ b/conftest.sh
@@ -101,7 +101,8 @@ test_header_presence() {
 build_cflags() {
     BASE_CFLAGS="-O2 -D__KERNEL__ \
 -DKBUILD_BASENAME=\"#conftest$$\" -DKBUILD_MODNAME=\"#conftest$$\" \
--nostdinc -isystem $ISYSTEM"
+-nostdinc -isystem $ISYSTEM -fshort-wchar  \
+-Wno-implicit-function-declaration -Wno-strict-prototypes"
 
     if [ "$OUTPUT" != "$SOURCES" ]; then
         OUTPUT_CFLAGS="-I$OUTPUT/include2 -I$OUTPUT/include"
@@ -4592,8 +4592,13 @@ compile_test() {
             #
             CODE="
             #include <drm/drm_gem.h>
+            #if defined(NV_LINUX_IOSYS_MAP_H_PRESENT)
+            typedef struct iosys_map nv_sysio_map_t;
+            #else
+            typedef struct dma_buf_map nv_sysio_map_t;
+            #endif
             int conftest_drm_gem_object_vmap_has_map_arg(
-                    struct drm_gem_object *obj, struct dma_buf_map *map) {
+                    struct drm_gem_object *obj, nv_sysio_map_t *map) {
                 return obj->funcs->vmap(obj, map);
             }"