diff --git a/texmf/tex/latex/astron/escape.cls b/texmf/tex/latex/astron/escape.cls
index 04753690272134f2d66952b260a17aebe3d856af..a9cd4113a6f97206210b38fbd9f28be2da6447f5 100644
--- a/texmf/tex/latex/astron/escape.cls
+++ b/texmf/tex/latex/astron/escape.cls
@@ -81,15 +81,15 @@
 \input{common}
 
 % Default font for ESCAPE documents is Calibri
-% But if we can't find it (e.g. in CI), don't worry about it
+% But if we can't find it (e.g. in CI), fall back to Arial (if available)
 % Attempt to cache the results of the font check; it is very slow
-\newcommand{\useCalibri}{}
-\IfFontExistsTF{Calibri}{\renewcommand{\useCalibri}{\setmainfont{Calibri}}}{}
 \newcommand{\useArial}{}
-\IfFontExistsTF{Arial}{\renewcommand{\useArial}{\setmainfont{Arial}}}{}
+\IfFontExistsTF{Arial}{\renewcommand{\useArial}{\setsansfont{Arial}}}{}
+\newcommand{\useCalibri}{}
+\IfFontExistsTF{Calibri}{\renewcommand{\useCalibri}{\setsansfont{Calibri}}}{\useArial}
+\renewcommand{\familydefault}{\sfdefault}
 \useCalibri
 
-
 %
 % Define headers and footers
 %