diff --git a/storage/connect/os.h b/storage/connect/os.h
index 90e8eea1141..52eed14df0f 100644
--- a/storage/connect/os.h
+++ b/storage/connect/os.h
@@ -28,7 +28,13 @@ typedef char *LPTSTR;
 typedef char *PSZ;
 typedef int INT;
 #if !defined(NODW)
-typedef unsigned int DWORD;
+/*
+  sqltypes.h from unixODBC incorrectly defines
+  DWORD as "unsigned int" instead of "unsigned long" on 64-bit platforms.
+  Add "#define NODW" into all files including this file that include
+  sqltypes.h (through sql.h or sqlext.h).
+*/
+typedef unsigned long DWORD;
 #endif   /* !NODW */
 #undef  HANDLE     
 typedef int   HANDLE;
diff --git a/storage/connect/tabodbc.cpp b/storage/connect/tabodbc.cpp
index caec386d683..0b45691bcc3 100644
--- a/storage/connect/tabodbc.cpp
+++ b/storage/connect/tabodbc.cpp
@@ -46,12 +46,12 @@
 #else
 #if defined(UNIX)
 #include <errno.h>
+#define NODW
 #include "osutil.h"
 #else
 #include <io.h>
 #endif
 #include <fcntl.h>
-#define NODW
 #endif
 
 /***********************************************************************/