diff --git a/sys/platform/pc32/include/vmparam.h b/sys/platform/pc32/include/vmparam.h
index d5c378f..1c5e6f63 100644
--- a/sys/platform/pc32/include/vmparam.h
+++ b/sys/platform/pc32/include/vmparam.h
@@ -99,7 +99,7 @@
 #define UPT_MAX_ADDRESS		VADDR(PTDPTDI, PTDPTDI)
 #define UPT_MIN_ADDRESS		VADDR(PTDPTDI, 0)
 
-#define VM_MIN_USER_ADDRESS	((vm_offset_t)0)
+#define VM_MIN_USER_ADDRESS	((vm_offset_t)PAGE_SIZE)
 #define VM_MAX_USER_ADDRESS	VADDR(PTDPTDI, 0)
 
 #define USRSTACK		VM_MAX_USER_ADDRESS
diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c
index 9e790d2..e43372a 100644
--- a/sys/vm/vm_mmap.c
+++ b/sys/vm/vm_mmap.c
@@ -697,7 +697,7 @@ sys_madvise(struct madvise_args *uap)
 		return (EINVAL);
 	if (VM_MAX_USER_ADDRESS > 0 && tmpaddr > VM_MAX_USER_ADDRESS)
 		return (EINVAL);
-	if (VM_MIN_USER_ADDRESS > 0 && uap->addr < VM_MIN_USER_ADDRESS)
+	if (VM_MIN_USER_ADDRESS > 0 && (vm_offset_t) uap->addr < VM_MIN_USER_ADDRESS)
 		return (EINVAL);
 
 	/*
@@ -740,7 +740,7 @@ sys_mcontrol(struct mcontrol_args *uap)
 		return (EINVAL);
 	if (VM_MAX_USER_ADDRESS > 0 && tmpaddr > VM_MAX_USER_ADDRESS)
 		return (EINVAL);
-	if (VM_MIN_USER_ADDRESS > 0 && uap->addr < VM_MIN_USER_ADDRESS)
+	if (VM_MIN_USER_ADDRESS > 0 && (vm_offset_t) uap->addr < VM_MIN_USER_ADDRESS)
 		return (EINVAL);
 
 	/*
diff --git a/sys/vm/vm_vmspace.c b/sys/vm/vm_vmspace.c
index 9f8d7bb..bfd273f 100644
--- a/sys/vm/vm_vmspace.c
+++ b/sys/vm/vm_vmspace.c
@@ -502,7 +502,7 @@ sys_vmspace_mcontrol(struct vmspace_mcontrol_args *uap)
 		error = EINVAL;
 		goto done1;
 	}
-        if (VM_MIN_USER_ADDRESS > 0 && uap->addr < VM_MIN_USER_ADDRESS) {
+        if (VM_MIN_USER_ADDRESS > 0 && (vm_offset_t)uap->addr < VM_MIN_USER_ADDRESS) {
 		error = EINVAL;
 		goto done1;
 	}