@andlaus 
>  IMO, it [ERT] is quite similar to tinyXML prerequisite-wise

I agree.

> would you mind moving it up a few lines?

I'd rather move the "opm-parser" request *down* a few lines to achieve the same effect.  I'm currently testing the following patch.  Any thoughts?
```diff
diff --git a/cmake/Modules/opm-core-prereqs.cmake b/cmake/Modules/opm-core-prere
index 58b627e..b648b91 100644
--- a/cmake/Modules/opm-core-prereqs.cmake
+++ b/cmake/Modules/opm-core-prereqs.cmake
@@ -25,11 +25,11 @@ set (opm-core_DEPS
        "SuperLU"
        # xml processing (for config parsing)
        "TinyXML"
-       #Parser library
-       "opm-parser REQUIRED"
        # Ensembles-based Reservoir Tools (ERT)
        "ERT"
        # DUNE dependency
        "dune-common"
        "dune-istl"
+       #Parser library
+       "opm-parser REQUIRED"
        )
```