diff --git a/firmware/ihex2fw.c b/firmware/ihex2fw.c
index ba0cf0b..cf38e15 100644
--- a/firmware/ihex2fw.c
+++ b/firmware/ihex2fw.c
@@ -124,8 +124,7 @@
 	if (process_ihex(data, st.st_size))
 		return 1;
 
-	output_records(outfd);
-	return 0;
+	return output_records(outfd);
 }
 
 static int process_ihex(uint8_t *data, ssize_t size)
@@ -269,11 +268,13 @@
 
 		p->addr = htonl(p->addr);
 		p->len = htons(p->len);
-		write(outfd, &p->addr, writelen);
+		if (write(outfd, &p->addr, writelen) != writelen)
+			return 1;
 		p = p->next;
 	}
 	/* EOF record is zero length, since we don't bother to represent
 	   the type field in the binary version */
-	write(outfd, zeroes, 6);
+	if (write(outfd, zeroes, 6) != 6)
+		return 1;
 	return 0;
 }