diff --git a/etc/platform-configs/laki/package-list b/etc/platform-configs/laki/package-list
index 609b5a0..a38ec7b 100644
--- a/etc/platform-configs/laki/package-list
+++ b/etc/platform-configs/laki/package-list
@@ -69,3 +69,6 @@ performance/vampirtrace/(5.14.3,5.14.4):	mpi/openmpi/(1.7.1)  | cuda/(4.2,5.0) |
 # specify module tags in []
 # be aware of default->version association; current and past!
 # compiler/gnu/(4.6.3[testing],4.7.3[default]):
+# the following two lines are then identical:
+# mpi/openmpi/1.6.4: compiler/gnu/4.6.3
+# mpi/openmpi/1.6.4: compiler/gnu/testing