diff --git a/tex/iris.sty b/tex/iris.sty
index d802c81107c444551c1152f07028739adaa2f6b2..0704079a9913eb808f7fb171194352f81c7d018b 100644
--- a/tex/iris.sty
+++ b/tex/iris.sty
@@ -194,7 +194,7 @@
 \newcommand{\exclusive}{\textlog{exclusive}}
 
 \newcommand{\mupd}{\rightsquigarrow}
-\newcommand{\lupd}{\rightsquigarrow_{\mathfrak{L}}}
+\newcommand{\lupd}{\rightsquigarrow_{\textlog{L}}}
 \newcommand{\mincl}[1][]{%
   \ensuremath{\mathrel{\vbox{\offinterlineskip\ialign{%
     \hfil##\hfil\cr