diff --git a/src/sparse_sys.h b/src/sparse_sys.h
index aadaedf56..8b90e0dcd 100644
--- a/src/sparse_sys.h
+++ b/src/sparse_sys.h
@@ -26,11 +26,6 @@
 extern "C" {
 #endif
 
-#if defined(MATLAB_MEX_FILE) && MATLAB_MEX_FILE
-#include <mex.h>
-#undef  MAT_SIZE_T
-#define MAT_SIZE_T mwSignedIndex
-#endif
 
 #ifndef MAT_SIZE_T
 #define MAT_SIZE_T int