diff --git a/lib/libc/io/unistd/mmap.c b/lib/libc/io/unistd/mmap.c
index 03e4d67..7845e17 100644
--- a/lib/libc/io/unistd/mmap.c
+++ b/lib/libc/io/unistd/mmap.c
@@ -57,6 +57,24 @@ static int get_vmo(
 	return err;
 }
 
+static void *mreserve(kern_handle_t address_space, void *addr, size_t length)
+{
+	virt_addr_t base = (virt_addr_t)addr;
+	if (!base) {
+		base = MAP_ADDRESS_ANY;
+	}
+
+	kern_status_t status
+		= address_space_reserve(address_space, base, length, &base);
+
+	if (status != KERN_OK) {
+		__set_errno(__errno_from_kern_status(status));
+		return MAP_FAILED;
+	}
+
+	return (void *)base;
+}
+
 void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)
 {
 	int tmp = 0;
@@ -105,6 +123,12 @@ void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)
 		return MAP_FAILED;
 	}
 
+	if ((flags & (MAP_ANONYMOUS | MAP_PRIVATE)) && (prot == PROT_NONE)) {
+		void *ret = mreserve(address_space, addr, length);
+		kern_handle_close(address_space);
+		return ret;
+	}
+
 	kern_handle_t vmo = KERN_HANDLE_INVALID;
 	int err = get_vmo(fd, prot, flags, length, &vmo);
 	if (err != SUCCESS) {