diff --git a/extra/infix/infix.factor b/extra/infix/infix.factor
index 96887687dc..9c2613004a 100644
--- a/extra/infix/infix.factor
+++ b/extra/infix/infix.factor
@@ -120,3 +120,6 @@ PRIVATE>
 
 SYNTAX: [infix
     "infix]" [infix-parse suffix! \ call suffix! ;
+
+SYNTAX: infix[
+    "]" [infix-parse suffix! \ call suffix! ;