diff --git a/kernel/conftest.sh b/kernel/conftest.sh
index a9db899..4da7588 100755
--- a/kernel/conftest.sh
+++ b/kernel/conftest.sh
@@ -4464,20 +4464,22 @@ compile_test() {
             compile_check_conftest "$CODE" "NV_DRM_GEM_OBJECT_VMAP_HAS_MAP_ARG" "" "types"
         ;;
 
-        unsafe_follow_pfn)
+        follow_pfn)
             #
-            # Determine if unsafe_follow_pfn() is present.
+            # Determine if follow_pfn() is present.
             #
-            # unsafe_follow_pfn() was added by commit 69bacee7f9ad
-            # ("mm: Add unsafe_follow_pfn") in v5.13-rc1.
+            # follow_pfn() was added by commit 3b6748e2dd69
+            # ("mm: introduce follow_pfn()") in v2.6.31-rc1, and removed
+            # by commit 233eb0bf3b94 ("mm: remove follow_pfn")
+            # from linux-next 233eb0bf3b94.
             #
             CODE="
             #include <linux/mm.h>
-            void conftest_unsafe_follow_pfn(void) {
-                unsafe_follow_pfn();
+            void conftest_follow_pfn(void) {
+                follow_pfn();
             }"
 
-            compile_check_conftest "$CODE" "NV_UNSAFE_FOLLOW_PFN_PRESENT" "" "functions"
+            compile_check_conftest "$CODE" "NV_FOLLOW_PFN_PRESENT" "" "functions"
         ;;
 
         drm_plane_atomic_check_has_atomic_state_arg)
diff --git a/kernel/nvidia/nvidia.Kbuild b/kernel/nvidia/nvidia.Kbuild
index d6995ca..3a3dd17 100644
--- a/kernel/nvidia/nvidia.Kbuild
+++ b/kernel/nvidia/nvidia.Kbuild
@@ -165,7 +165,7 @@ NV_CONFTEST_FUNCTION_COMPILE_TESTS += ktime_get_raw_ts64
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += ktime_get_real_ts64
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += ioremap_nocache
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += vga_tryget
-NV_CONFTEST_FUNCTION_COMPILE_TESTS += unsafe_follow_pfn
+NV_CONFTEST_FUNCTION_COMPILE_TESTS += follow_pfn
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += acpi_bus_get_device
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += acpi_video_backlight_use_native
 
diff --git a/kernel/nvidia/os-mlock.c b/kernel/nvidia/os-mlock.c
index f88daed..9e1bd0c 100644
--- a/kernel/nvidia/os-mlock.c
+++ b/kernel/nvidia/os-mlock.c
@@ -18,10 +18,10 @@ static inline int nv_follow_pfn(struct vm_area_struct *vma,
                                 unsigned long address,
                                 unsigned long *pfn)
 {
-#if defined(NV_UNSAFE_FOLLOW_PFN_PRESENT)
-    return unsafe_follow_pfn(vma, address, pfn);
-#else
+#if defined(NV_FOLLOW_PFN_PRESENT)
     return follow_pfn(vma, address, pfn);
+#else
+    return -1;
 #endif
 }