diff --git a/cmake/Modules/Packages/MACHDYN.cmake b/cmake/Modules/Packages/MACHDYN.cmake
index 8729d80dbf..d90ca8146c 100644
--- a/cmake/Modules/Packages/MACHDYN.cmake
+++ b/cmake/Modules/Packages/MACHDYN.cmake
@@ -8,7 +8,7 @@ option(DOWNLOAD_EIGEN3 "Download Eigen3 instead of using an already installed on
 if(DOWNLOAD_EIGEN3)
   message(STATUS "Eigen3 download requested - we will build our own")
 
-  set(EIGEN3_URL "https://download.lammps.org/thirdparty/eigen-3.4.0.tar.gz" CACHE STRING "URL for Eigen3 tarball")
+  set(EIGEN3_URL "${LAMMPS_THIRDPARTY_URL}/eigen-3.4.0.tar.gz" CACHE STRING "URL for Eigen3 tarball")
   set(EIGEN3_MD5 "4c527a9171d71a72a9d4186e65bea559" CACHE STRING "MD5 checksum of Eigen3 tarball")
   mark_as_advanced(EIGEN3_URL)
   mark_as_advanced(EIGEN3_MD5)
diff --git a/tools/offline/scripts/init_http_cache.sh b/tools/offline/scripts/init_http_cache.sh
index b003aa08b3..926a74f499 100755
--- a/tools/offline/scripts/init_http_cache.sh
+++ b/tools/offline/scripts/init_http_cache.sh
@@ -45,7 +45,7 @@ SCAFACOS_FIX_URL="${LAMMPS_THIRDPARTY_URL}/scafacos-1.0.1-fix.diff"
 GTEST_URL="https://github.com/google/googletest/archive/release-1.11.0.tar.gz"
 YAML_URL="https://pyyaml.org/download/libyaml/yaml-0.2.5.tar.gz"
 MATHJAX_URL="https://github.com/mathjax/MathJax/archive/3.1.3.tar.gz"
-EIGEN3_URL="https://download.lammps.org/thirdparty/eigen-3.4.0.tar.gz"
+EIGEN3_URL="${LAMMPS_THIRDPARTY_URL}/eigen-3.4.0.tar.gz"
 CUB_URL="https://github.com/NVlabs/cub/archive/1.12.0.tar.gz"
 KOKKOS_URL="https://github.com/kokkos/kokkos/archive/3.4.01.tar.gz"
 KIM_URL="https://s3.openkim.org/kim-api/kim-api-2.2.1.txz"