diff --git a/maintainer/pineappl-ci/script.sh b/maintainer/pineappl-ci/script.sh
index 61fa4727..c27f2019 100755
--- a/maintainer/pineappl-ci/script.sh
+++ b/maintainer/pineappl-ci/script.sh
@@ -22,8 +22,9 @@ cargo install cargo-c --version ${CARGOC_V} --features=vendored-openssl
 # remove files generated by cargo
 rm -r /usr/local/cargo/registry
 
-# install LHAPDF
-curl "https://lhapdf.hepforge.org/downloads/?f=LHAPDF-${LHAPDF_V}.tar.gz" | tar xzf -
+# install LHAPDF - use Wayback Machine as a mirror if hepforge is offline
+( curl "https://lhapdf.hepforge.org/downloads/?f=LHAPDF-${LHAPDF_V}.tar.gz" || \
+    curl "https://web.archive.org/web/20211018095814/https://lhapdf.hepforge.org/downloads/?f=LHAPDF-6.4.0.tar.gz" ) | tar xzf -
 cd LHAPDF-${LHAPDF_V}
 ./configure --disable-python --disable-static
 make -j