diff --git a/defs.h b/defs.h
index 90b5572..12f021b 100644
--- a/defs.h
+++ b/defs.h
@@ -164,7 +164,7 @@ void            uartputc(int);
 void            seginit(void);
 void            kvmalloc(void);
 void            vmenable(void);
-pde_t*          setupkvm();
+pde_t*          setupkvm(void);
 char*           uva2ka(pde_t*, char*);
 int             allocuvm(pde_t*, uint, uint);
 int             deallocuvm(pde_t*, uint, uint);
diff --git a/exec.c b/exec.c
index 312a5c3..a85e203 100644
--- a/exec.c
+++ b/exec.c
@@ -29,7 +29,7 @@ exec(char *path, char **argv)
   if(elf.magic != ELF_MAGIC)
     goto bad;
 
-  if((pgdir = setupkvm(kalloc)) == 0)
+  if((pgdir = setupkvm()) == 0)
     goto bad;
 
   // Load program into memory.
diff --git a/proc.c b/proc.c
index 05cb85f..bcdbfea 100644
--- a/proc.c
+++ b/proc.c
@@ -83,7 +83,7 @@ userinit(void)
   
   p = allocproc();
   initproc = p;
-  if((p->pgdir = setupkvm(kalloc)) == 0)
+  if((p->pgdir = setupkvm()) == 0)
     panic("userinit: out of memory?");
   inituvm(p->pgdir, _binary_initcode_start, (int)_binary_initcode_size);
   p->sz = PGSIZE;
diff --git a/vm.c b/vm.c
index fa7b706..da3ea3c 100644
--- a/vm.c
+++ b/vm.c
@@ -126,7 +126,7 @@ static struct kmap {
 
 // Set up kernel part of a page table.
 pde_t*
-setupkvm()
+setupkvm(void)
 {
   pde_t *pgdir;
   struct kmap *k;