diff --git a/cmake/EigenTesting.cmake b/cmake/EigenTesting.cmake
index d140fe6e8e99fae3c4a3acf4cc7a90dc5c176c3d..2a44f05c3e756b66610f4a13c857b90e5032674b 100644
--- a/cmake/EigenTesting.cmake
+++ b/cmake/EigenTesting.cmake
@@ -75,7 +75,7 @@ macro(ei_add_test_internal testname testname_with_suffix)
 
   # let the user pass flags.
   if(${ARGC} GREATER 2)
-    separate_arguments(compile_options NATIVE_COMMAND ${ARGV2})
+    separate_arguments(compile_options NATIVE_COMMAND "${ARGV2}")
     target_compile_options(${targetname} PRIVATE ${compile_options})
   endif()