diff --git a/docker/gcc-ubuntu/spack.yaml b/docker/gcc-ubuntu/spack.yaml
index abce0d46..3ec10ced 100644
--- a/docker/gcc-ubuntu/spack.yaml
+++ b/docker/gcc-ubuntu/spack.yaml
@@ -50,7 +50,7 @@ spack:
         cflags: -pthread
         cxxflags: -pthread
       modules: []
-      operating_system: ubuntu22.04
+      operating_system: ubuntu20.04
       paths:
         cc: /usr/bin/gcc-10
         cxx: /usr/bin/g++-10
@@ -65,7 +65,7 @@ spack:
         cflags: -pthread
         cxxflags: -pthread
       modules: []
-      operating_system: ubuntu22.04
+      operating_system: ubuntu20.04
       paths:
         cc: /usr/bin/gcc-9
         cxx: /usr/bin/g++-9