diff --git a/.gitlab/docker/Dockerfile.spack_build b/.gitlab/docker/Dockerfile.spack_build
index b63f193a0..7889b3563 100644
--- a/.gitlab/docker/Dockerfile.spack_build
+++ b/.gitlab/docker/Dockerfile.spack_build
@@ -30,7 +30,6 @@ RUN spack -e pika_ci config add "config:flags:keep_werror:all" && \
 
 # Run compile only tests and tests.unit.build, submit ctest metrics to elastic
 ARG SPACK_ARCH
-ARG BUILD_TYPE
 ARG CI_COMMIT_AUTHOR
 ARG CI_COMMIT_BRANCH
 ARG CI_COMMIT_DESCRIPTION