diff --git a/bits/87_read.js b/bits/87_read.js
index 615400f..ade1567 100644
--- a/bits/87_read.js
+++ b/bits/87_read.js
@@ -82,7 +82,7 @@ function readSync(data/*:RawData*/, opts/*:?ParseOpts*/)/*:Workbook*/ {
 	}
 	switch((n = firstbyte(d, o))[0]) {
 		case 0xD0: return read_cfb(CFB.read(d, o), o);
-		case 0x09: return parse_xlscfb(d, o);
+		case 0x09: if(n[1] <= 0x04) return parse_xlscfb(d, o); break;
 		case 0x3C: return parse_xlml(d, o);
 		case 0x49: if(n[1] === 0x44) return read_wb_ID(d, o); break;
 		case 0x54: if(n[1] === 0x41 && n[2] === 0x42 && n[3] === 0x4C) return DIF.to_workbook(d, o); break;