diff --git a/spack.yaml b/spack.yaml
index ab00b837..100103f6 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -2,11 +2,17 @@
 #
 # It describes a set of packages to be installed, along with
 # configuration settings.
-# Instructions for editing this file are found in 
+# Instructions for editing this file are found in
 # https://github.com/ACCESS-NRI/model-deployment-template/blob/main/spack.yaml
 spack:
   specs:
-    - access-om3@git.2025.08.001
+    # used to have: - access-om3@git.2025.08.001
+    # Jbisits MOM6 code https://github.com/jbisits/MOM6/commit/6e705048aa6b400ee7630ef8e2be94d415fff86f
+    # =2025.07.000 means spack will use that set of dependencies to concretise
+    # see https://github.com/ACCESS-NRI/spack-packages/blob/fd44ae03141eab221ce0e5b587dbb9c81d411fcb/packages/access-mom6/package.py#L27
+    # link regarding the Debug flag https://spack-tutorial.readthedocs.io/en/latest/tutorial_buildsystems.html#cmake
+    - access-mom6@git.6e705048aa6b400ee7630ef8e2be94d415fff86f=2025.07.000 fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll" cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll" cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll" ~access3
+    # - access-mom6@git.6e705048aa6b400ee7630ef8e2be94d415fff86f=2025.07.000 fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll" cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll" cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll" ~access3 build_type=Debug
   packages:
     # Main Dependencies
     access3:
@@ -29,6 +35,8 @@ spack:
         - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
         - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
         - 'cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
+      package_attributes:
+        git: https://github.com/jbisits/MOM6.git
     access-ww3:
       require:
         - '@2025.08.000'