diff --git a/sbin/fdisk/fdisk.c b/sbin/fdisk/fdisk.c
index 604cc7d6be9..1e121bb6450 100644
--- a/sbin/fdisk/fdisk.c
+++ b/sbin/fdisk/fdisk.c
@@ -1066,8 +1066,8 @@ process_geometry(CMD *command)
 	    warnx("ERROR line %d: number of heads not specified",
 		    current_line_number);
 	    status = 0;
-	    } else if (dos_heads > 255) {
-	    warnx("ERROR line %d: number of heads must be within (1-255)",
+	    } else if (dos_heads > 256) {
+	    warnx("ERROR line %d: number of heads must be within (1-256)",
 		    current_line_number);
 	    status = 0;
 	}