diff --git a/cmake/Modules/OpmLibMain.cmake b/cmake/Modules/OpmLibMain.cmake
index ad2e4d5d0..5dcf193d3 100644
--- a/cmake/Modules/OpmLibMain.cmake
+++ b/cmake/Modules/OpmLibMain.cmake
@@ -91,7 +91,7 @@ find_and_append_package_list_to (${project} ${${project}_DEPS})
 
 # remove the dependency on the testing framework from the main library;
 # it is not possible to query for Boost twice with different components.
-list (REMOVE_ITEM ${project}_LIBRARIES ${Boost_UNIT_TEST_FRAMEWORK_LIBRARY})
+list (REMOVE_ITEM "${project}_LIBRARIES" "${Boost_UNIT_TEST_FRAMEWORK_LIBRARY}")
 
 # don't import more libraries than we need to
 include (UseOnlyNeeded)