diff --git a/tools/fasc.pl b/tools/fasc.pl
index 3a761fa..9ba75dd 100644
--- a/tools/fasc.pl
+++ b/tools/fasc.pl
@@ -38,7 +38,7 @@ use Bit::Vector;
 
 my %encoding = (
   0 => "00001",
-  1 => "10000",
+  1 => "00010",
   2 => "00100",
   3 => "00111",
   4 => "01000",