diff --git a/drivers/mtd_flashpage/mtd_flashpage.c b/drivers/mtd_flashpage/mtd_flashpage.c
index bf5f58997b..2bfc34789c 100644
--- a/drivers/mtd_flashpage/mtd_flashpage.c
+++ b/drivers/mtd_flashpage/mtd_flashpage.c
@@ -44,6 +44,12 @@ static int _read(mtd_dev_t *dev, void *buf, uint32_t addr, uint32_t size)
 
     (void)dev;
 
+#ifndef CPU_HAS_UNALIGNED_ACCESS
+    if (addr % sizeof(uword_t)) {
+        return -EINVAL;
+    }
+#endif
+
     uword_t dst_addr = addr;
     memcpy(buf, (void *)dst_addr, size);