diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index 8a09aafbf246b5059b6d6d7ec0d3bcc16448b66d..51b10263b8824e947c4c4cdbbd272fb1eb2fb46b 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -219,7 +219,7 @@ int dfu_write(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
 			ret = tret;
 	}
 
-	return ret = 0 ? size : ret;
+	return ret;
 }
 
 static int dfu_read_buffer_fill(struct dfu_entity *dfu, void *buf, int size)