diff --git a/MathLib/CMakeLists.txt b/MathLib/CMakeLists.txt
index 05603a7f63c0fe792d896c0610357efb1019733b..e5e1cd9c50e61d2161f19d91ec166cc50e3e804f 100644
--- a/MathLib/CMakeLists.txt
+++ b/MathLib/CMakeLists.txt
@@ -60,5 +60,5 @@ target_compile_definitions(MathLib
     $<$<BOOL:${OGS_USE_EIGEN}>:OGS_USE_EIGEN>
     $<$<BOOL:${CVODE_FOUND}>:CVODE_FOUND>
     PRIVATE
-    $<$<BOOL:${USE_MKL}>:USE_MKL>
+    $<$<BOOL:${OGS_USE_MKL}>:USE_MKL>
 )