diff --git a/gap-pkg-jupyterviz.spec b/gap-pkg-jupyterviz.spec
index ac033ca..904605a 100644
--- a/gap-pkg-jupyterviz.spec
+++ b/gap-pkg-jupyterviz.spec
@@ -36,6 +36,7 @@ This package contains documentation for gap-pkg-%{pkgname}.
 %autosetup -p0 -n %{pkgname}-%{version}
 
 %build
+export LC_ALL=C.UTF-8
 python3 extract_examples.py
 gap < makedoc.g
 
@@ -46,6 +47,7 @@ cp -a doc examples lib tst *.g *.ipynb \
 rm -f %{buildroot}%{_gap_dir}/pkg/%{pkgname}-%{version}/doc/*.{aux,bbl,blg,idx,ilg,ind,log,out,pnr,tex}
 
 %check
+export LC_ALL=C.UTF-8
 gap -l "%{buildroot}%{_gap_dir};%{_gap_dir}" < tst/testall.g
 
 %files