diff --git a/lib/slab.c b/lib/slab.c
index c3947162..c4ccbd37 100644
--- a/lib/slab.c
+++ b/lib/slab.c
@@ -213,7 +213,7 @@ sl_new(pool *p, uint size)
       + sizeof(u32) * s->head_bitfield_len
       + align - 1)
     / align * align;
-  } while (s->objs_per_slab * size + s->head_size > page_size);
+  } while (s->objs_per_slab * size + s->head_size > (uint) page_size);
 
   if (!s->objs_per_slab)
     bug("Slab: object too large");
diff --git a/sysdep/unix/coroutine.c b/sysdep/unix/coroutine.c
index 4747d01a..2068afd5 100644
--- a/sysdep/unix/coroutine.c
+++ b/sysdep/unix/coroutine.c
@@ -86,7 +86,7 @@ uint dg_order(struct domain_generic *dg)
 
 void do_lock(struct domain_generic *dg, struct domain_generic **lsp)
 {
-  if ((char *) lsp - (char *) &locking_stack != dg->order)
+  if ((char *) lsp - (char *) &locking_stack != (int) dg->order)
     bug("Trying to lock on bad position: order=%u, lsp=%p, base=%p", dg->order, lsp, &locking_stack);
 
   if (lsp <= last_locked)
@@ -110,7 +110,7 @@ void do_lock(struct domain_generic *dg, struct domain_generic **lsp)
 
 void do_unlock(struct domain_generic *dg, struct domain_generic **lsp)
 {
-  if ((char *) lsp - (char *) &locking_stack != dg->order)
+  if ((char *) lsp - (char *) &locking_stack != (int) dg->order)
     bug("Trying to unlock on bad position: order=%u, lsp=%p, base=%p", dg->order, lsp, &locking_stack);
 
   if (dg->locked_by != &locking_stack)