diff --git a/gnu/packages/education.scm b/gnu/packages/education.scm
index 0d1a1c40be..bac3148c54 100644
--- a/gnu/packages/education.scm
+++ b/gnu/packages/education.scm
@@ -977,6 +977,9 @@ (define-public tuxmath
        ;; Unbundle fonts.
        (snippet
         `(begin
+           ;; Remove duplicate definition.
+           (substitute* "src/menu_lan.c"
+             (("lan_player_type.*MAX_CLIENTS\\];") ""))
            (for-each delete-file (find-files "data/fonts" "\\.ttf$"))
            #t))))
     (build-system gnu-build-system)