diff --git a/mm/filemap.c b/mm/filemap.c
index ceba0bd..538b75e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1374,7 +1374,7 @@
 	return 0;
 }
 
-asmlinkage ssize_t sys_readahead(int fd, loff_t offset, size_t count)
+asmlinkage long sys_readahead(int fd, loff_t offset, size_t count)
 {
 	ssize_t ret;
 	struct file *file;
diff --git a/mm/mmap.c b/mm/mmap.c
index 7496231..a970d89 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -245,7 +245,7 @@
 	return next;
 }
 
-asmlinkage unsigned long sys_brk(unsigned long brk)
+asmlinkage long sys_brk(unsigned long brk)
 {
 	unsigned long rlim, retval;
 	unsigned long newbrk, oldbrk;
diff --git a/mm/mremap.c b/mm/mremap.c
index 646de95..5572e08 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -420,7 +420,7 @@
 	return ret;
 }
 
-asmlinkage unsigned long sys_mremap(unsigned long addr,
+asmlinkage long sys_mremap(unsigned long addr,
 	unsigned long old_len, unsigned long new_len,
 	unsigned long flags, unsigned long new_addr)
 {
diff --git a/mm/nommu.c b/mm/nommu.c
index 60ed837..ee3e789 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -416,7 +416,7 @@
  *  to a regular file.  in this case, the unmapping will need
  *  to invoke file system routines that need the global lock.
  */
-asmlinkage unsigned long sys_brk(unsigned long brk)
+asmlinkage long sys_brk(unsigned long brk)
 {
 	struct mm_struct *mm = current->mm;