diff --git a/drivers/io/io_memmap.c b/drivers/io/io_memmap.c
index 5104fb1..a97df6b 100644
--- a/drivers/io/io_memmap.c
+++ b/drivers/io/io_memmap.c
@@ -125,8 +125,6 @@
 	int result = -ENOMEM;
 	const io_block_spec_t *block_spec = (io_block_spec_t *)spec;
 
-	assert(block_spec->length >= 0);
-
 	/* Since we need to track open state for seek() we only allow one open
 	 * spec at a time. When we have dynamic memory we can malloc and set
 	 * entity->info.