diff --git a/flash_eraseall.c b/flash_eraseall.c
index 3da56ee..0a4010e 100644
--- a/flash_eraseall.c
+++ b/flash_eraseall.c
@@ -60,12 +60,25 @@ static int clmlen = 8;
 
 static int prepare_clean_marker(mtd_info_t *meminfo)
 {
+	struct nand_oobinfo oobinfo;
+
 	cleanmarker.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 	cleanmarker.nodetype = cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER);
-	if (meminfo->type != MTD_NANDFLASH)
+
+	switch (meminfo->type) {
+	case MTD_ROM:
+	case MTD_RAM:
+	case MTD_NORFLASH:
 		cleanmarker.totlen = cpu_to_je32(sizeof(struct jffs2_unknown_node));
-	else {
-		struct nand_oobinfo oobinfo;
+		break;
+
+	case MTD_DATAFLASH:
+	case MTD_UBIVOLUME:
+		fprintf(stderr, "JFFS2 layout not supported on this flash.\n");
+		return -1;
+		break;
+
+	case MTD_NANDFLASH:
 
 		if (ioctl(fd, MEMGETOOBSEL, &oobinfo) != 0) {
 			fprintf(stderr, "%s: %s: unable to get NAND oobinfo\n",
@@ -103,6 +116,12 @@ static int prepare_clean_marker(mtd_info_t *meminfo)
 			}
 		}
 		cleanmarker.totlen = cpu_to_je32(8);
+		break;
+	default:
+		fprintf(stderr, "Unknown flash type, just erasing\n");
+		return -1;
+		break;
+
 	}
 	cleanmarker.hdr_crc = cpu_to_je32(crc32(0, &cleanmarker,
 				sizeof(struct jffs2_unknown_node) - 4));