diff --git a/TeXmacs/tests/tmu/80_9_math_font.tmu b/TeXmacs/tests/tmu/80_9_math_font.tmu
new file mode 100644
index 000000000..822b70146
--- /dev/null
+++ b/TeXmacs/tests/tmu/80_9_math_font.tmu
@@ -0,0 +1,17 @@
+<TMU|<tuple|1.0.5|1.2.9.5>>
+
+<style|<tuple|generic|chinese>>
+
+<\body>
+  <\equation*>
+    a+b
+  </equation*>
+</body>
+
+<\initial>
+  <\collection>
+    <associate|math-font|Stix Math>
+    <associate|page-medium|paper>
+    <associate|page-screen-margin|false>
+  </collection>
+</initial>
diff --git a/src/Graphics/Fonts/smart_font.cpp b/src/Graphics/Fonts/smart_font.cpp
index a6b755d16..e5acde898 100644
--- a/src/Graphics/Fonts/smart_font.cpp
+++ b/src/Graphics/Fonts/smart_font.cpp
@@ -1707,12 +1707,15 @@ font
 smart_font (string family, string variant, string series, string shape,
             string tfam, string tvar, string tser, string tsh, int sz,
             int dpi) {
+  if (tfam == "roman" || starts (tfam, "sys-")) {
+    tfam= family;
+  }
   if (variant != "mr") {
     if (variant == "ms") tvar= "ss";
     if (variant == "mt") tvar= "tt";
   }
   if (shape == "right") tsh= "mathupright";
-  return smart_font (family, tvar, tser, tsh, sz, dpi);
+  return smart_font (tfam, tvar, tser, tsh, sz, dpi);
 }
 
 static string