diff --git a/sys/compat/linuxkpi/common/include/linux/mm.h b/sys/compat/linuxkpi/common/include/linux/mm.h
index 6f67a0ba4b41..c2ccb4cb96ad 100644
--- a/sys/compat/linuxkpi/common/include/linux/mm.h
+++ b/sys/compat/linuxkpi/common/include/linux/mm.h
@@ -257,16 +257,6 @@ vm_get_page_prot(unsigned long vm_flags)
 	return (vm_flags & VM_PROT_ALL);
 }
 
-extern int vm_insert_mixed(struct vm_area_struct *, unsigned long addr, pfn_t pfn);
-
-extern int
-vm_insert_pfn(struct vm_area_struct *, unsigned long addr,
-    unsigned long pfn);
-
-extern int
-vm_insert_pfn_prot(struct vm_area_struct *, unsigned long addr,
-    unsigned long pfn, pgprot_t pgprot);
-
 static inline vm_page_t
 vmalloc_to_page(const void *addr)
 {