diff --git a/.github/workflows/latexdiff.yml b/.github/workflows/latexdiff.yml
index 2021d08..0d5f542 100644
--- a/.github/workflows/latexdiff.yml
+++ b/.github/workflows/latexdiff.yml
@@ -78,12 +78,11 @@ jobs:
         
       - name: Override “\input{preamble/fonts}” in diff.tex
         run: |
-          sed -i '/\\input{preamble\/fonts}/c\
-          % — replaced by CI: use TeX Gyre fonts instead of Times New Roman/Arial       \
-          \setmainfont{TeX Gyre Termes}                                                   \
-          \setsansfont{TeX Gyre Heros}                                                    \
-          \setmonofont{TeX Gyre Cursor}\
-          ' diff_output/diff.tex
+          sed -i "/\\input{preamble\/fonts}/c\\
+          % — replaced by CI: use TeX Gyre fonts instead of Times New Roman/Arial\\
+          \\setmainfont{TeX Gyre Termes}\\
+          \\setsansfont{TeX Gyre Heros}\\
+          \\setmonofont{TeX Gyre Cursor}" diff_output/diff.tex
           
       - name: Print preview of diff.tex (after font override)
         run: |