diff --git a/fs/partitions/msdos.c b/fs/partitions/msdos.c
index dafd3b6..78443e0 100644
--- a/fs/partitions/msdos.c
+++ b/fs/partitions/msdos.c
@@ -68,10 +68,10 @@
 	unsigned char *d;
 	int slot, ret = 0;
 
-	if (p[0] != AIX_LABEL_MAGIC1 &&
-		p[1] != AIX_LABEL_MAGIC2 &&
-		p[2] != AIX_LABEL_MAGIC3 &&
-		p[3] != AIX_LABEL_MAGIC4)
+	if (!(p[0] == AIX_LABEL_MAGIC1 &&
+		p[1] == AIX_LABEL_MAGIC2 &&
+		p[2] == AIX_LABEL_MAGIC3 &&
+		p[3] == AIX_LABEL_MAGIC4))
 		return 0;
 	/* Assume the partition table is valid if Linux partitions exists */
 	for (slot = 1; slot <= 4; slot++, pt++) {