diff --git a/gtsam/CMakeLists.txt b/gtsam/CMakeLists.txt
index 7e86e4bb8..495c3f39f 100644
--- a/gtsam/CMakeLists.txt
+++ b/gtsam/CMakeLists.txt
@@ -129,7 +129,9 @@ if (GTSAM_BUILD_WRAP)
     
     # Generate, build and install toolbox
     set(mexFlags "${GTSAM_BUILD_MEX_BINARY_FLAGS} ${CMAKE_CXX_FLAGS} -I${Boost_INCLUDE_DIR} -I${MEX_INCLUDE_ROOT} -I${MEX_INCLUDE_ROOT}/gtsam -I${MEX_INCLUDE_ROOT}/gtsam/base -I${MEX_INCLUDE_ROOT}/gtsam/geometry -I${MEX_INCLUDE_ROOT}/gtsam/linear -I${MEX_INCLUDE_ROOT}/gtsam/discrete -I${MEX_INCLUDE_ROOT}/gtsam/inference -I${MEX_INCLUDE_ROOT}/gtsam/nonlinear -I${MEX_INCLUDE_ROOT}/gtsam/slam -L${GTSAM_LIB_DIR} -lgtsam")
-    
+    string(TOUPPER "${CMAKE_BUILD_TYPE}" cmake_build_type_toupper)
+	set(mexFlags "${mexFlags} -g COMPFLAGS='/c /DMATLAB_MEX_FILE ${CMAKE_CXX_FLAGS_${cmake_build_type_toupper}}'")
+
     # Macro to handle details of setting up targets
     wrap_library(gtsam "${mexFlags}" "../")
 endif ()