diff --git a/mpcdf_common.py b/mpcdf_common.py
index 5fc127dbe7d595a0f83eb3bd2df1a20000a1219a..065f615ba9b09a19e45a1fe5f1f9fe7450af86ca 100644
--- a/mpcdf_common.py
+++ b/mpcdf_common.py
@@ -15,7 +15,10 @@ def valid_mpi(compiler, mpi):
     """
     It might be possible to use Intel MPI libararies and compilers from
     different Parallel Studio packages, but I currently do not want to support
-    it
+    it.
+
+    Take care to keep this in sync with the file 'macros.obs_cluster' of
+    the package software:dist / mpcdf_cluster_macros
     """
     if compiler == "intel_18_0":
         if mpi.startswith("impi"):
@@ -33,11 +36,14 @@ def valid_cuda(cuda, compiler):
     """
     The CUDA distribution only works with certain gcc versions,
     this little function takes care that only supported combinations
-    are allowed
+    are allowed.
+
+    Take care to keep this in sync with the file 'macros.obs_cluster' of
+    the package software:dist / mpcdf_cluster_macros
     """
-    if cuda == "cuda_8":
+    if cuda == "cuda_8_0":
         return compiler == "gcc_5"
-    if cuda == "cuda_9":
+    if cuda == "cuda_9_1":
         return compiler == "gcc_6"
     return False