diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b6873ab76052d74c6ce5bfe89e244ab88e9d97ff..0b09a810c2366ba7b359e18d1ed176ad917b8d85 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -121,7 +121,11 @@ spack:install_compilers:
       --use-cache
       ${COMPILER_LIST_SPECS}
 
-    - /spack/spack/bin/spack buildcache create --update-index --signed /buildcache ${COMPILER_LIST_SPECS}
+    - /spack/spack/bin/spack buildcache create
+      --update-index
+      --key EDC904DCE3D2E84E
+      /buildcache ${COMPILER_LIST_SPECS}
+
     - |
       echo 'definitions: [ compilers: [' ${COMPILER_LIST_SPECS} ']]' > compiler_definitions.yaml