diff --git a/mex/sources/dynmex.h b/mex/sources/dynmex.h
index bac4a55e1..52a71bef5 100644
--- a/mex/sources/dynmex.h
+++ b/mex/sources/dynmex.h
@@ -1,5 +1,5 @@
 /*
- * Copyright © 2009-2014 Dynare Team
+ * Copyright © 2009-2019 Dynare Team
  *
  * This file is part of Dynare.
  *
@@ -40,4 +40,8 @@
   } while (0)
 #endif
 
+#if defined(MATLAB_MEX_FILE) && MATLAB_VERSION < 0x0805
+# define mxIsScalar(x) (mxGetM(x) == 1 && mxGetN(x) == 1)
+#endif
+
 #endif