diff --git a/mm/filemap.c b/mm/filemap.c
index ab77e19ab09c0f447e932c1d63c1261b481289e0..9276bdb2343c73884c2be1c11dca5c5c462054ce 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2719,7 +2719,6 @@ int filemap_page_mkwrite(struct vm_fault *vmf)
 	sb_end_pagefault(inode->i_sb);
 	return ret;
 }
-EXPORT_SYMBOL(filemap_page_mkwrite);
 
 const struct vm_operations_struct generic_file_vm_ops = {
 	.fault		= filemap_fault,
@@ -2750,6 +2749,10 @@ int generic_file_readonly_mmap(struct file *file, struct vm_area_struct *vma)
 	return generic_file_mmap(file, vma);
 }
 #else
+int filemap_page_mkwrite(struct vm_fault *vmf)
+{
+	return -ENOSYS;
+}
 int generic_file_mmap(struct file * file, struct vm_area_struct * vma)
 {
 	return -ENOSYS;
@@ -2760,6 +2763,7 @@ int generic_file_readonly_mmap(struct file * file, struct vm_area_struct * vma)
 }
 #endif /* CONFIG_MMU */
 
+EXPORT_SYMBOL(filemap_page_mkwrite);
 EXPORT_SYMBOL(generic_file_mmap);
 EXPORT_SYMBOL(generic_file_readonly_mmap);