diff --git a/cmake/SetupBOUTThirdParty.cmake b/cmake/SetupBOUTThirdParty.cmake
index 850809e856..9e6bdc6d2a 100644
--- a/cmake/SetupBOUTThirdParty.cmake
+++ b/cmake/SetupBOUTThirdParty.cmake
@@ -362,7 +362,7 @@ if(BOUT_USE_SUNDIALS)
         CACHE BOOL "" FORCE
     )
     set(ENABLE_OPENMP
-        OFF
+        ${BOUT_USE_OPENMP}
         CACHE BOOL "" FORCE
     )
     if(BUILD_SHARED_LIBS)