diff --git a/cmake/Modules/OpmFiles.cmake b/cmake/Modules/OpmFiles.cmake
index 90910a0c3..fd4e126e0 100644
--- a/cmake/Modules/OpmFiles.cmake
+++ b/cmake/Modules/OpmFiles.cmake
@@ -39,6 +39,16 @@ macro (opm_sources opm)
   # names in the process
   foreach (_file IN LISTS MAIN_SOURCE_FILES)
 	list (APPEND ${opm}_SOURCES ${PROJECT_SOURCE_DIR}/${_file})
+	# further classify into language if some other modules need to add props
+	if (_file MATCHES ".*\\.[cC][a-zA-Z]*$")
+	  if (_file MATCHES ".*\\.c$")
+		list (APPEND ${opm}_C_SOURCES ${PROJECT_SOURCE_DIR}/${_file})
+	  else (_file MATCHES ".*\\.c$")
+		list (APPEND ${opm}_CXX_SOURCES ${PROJECT_SOURCE_DIR}/${_file})
+	  endif (_file MATCHES ".*\\.c$")
+	elseif (_file MATCHES ".*\\.[fF][a-zA-Z]*$")
+	  list (APPEND ${opm}_Fortran_SOURCES ${PROJECT_SOURCE_DIR}/${_file})
+	endif (_file MATCHES ".*\\.[cC][a-zA-Z]*$")
   endforeach (_file)
   foreach (_file IN LISTS PUBLIC_HEADER_FILES)
 	list (APPEND ${opm}_HEADERS ${PROJECT_SOURCE_DIR}/${_file})