diff --git a/portable/MSVC-MingW/portmacro.h b/portable/MSVC-MingW/portmacro.h
index 1a4cd1622..37bfb2586 100644
--- a/portable/MSVC-MingW/portmacro.h
+++ b/portable/MSVC-MingW/portmacro.h
@@ -145,22 +145,25 @@ void vPortExitCritical( void );
                          : "cc" )
 
     #else /* __GNUC__ */
+        #include <intrin.h>
 
         /* BitScanReverse returns the bit position of the most significant '1'
          * in the word. */
         #if defined( __x86_64__ ) || defined( _M_X64 )
+            #pragma intrinsic(_BitScanReverse64)
 
             #define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities )    \
             do                                                                      \
             {                                                                       \
-                DWORD ulTopPriority;                                                \
+                unsigned long ulTopPriority;                                        \
                 _BitScanReverse64( &ulTopPriority, ( uxReadyPriorities ) );         \
                 uxTopPriority = ulTopPriority;                                      \
             } while( 0 )
 
         #else /* #if defined( __x86_64__ ) || defined( _M_X64 ) */
+            #pragma intrinsic(_BitScanReverse)
 
-            #define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities )    _BitScanReverse( ( DWORD * ) &( uxTopPriority ), ( uxReadyPriorities ) )
+            #define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities )    _BitScanReverse( ( unsigned long * ) &( uxTopPriority ), ( uxReadyPriorities ) )
 
         #endif /* #if defined( __x86_64__ ) || defined( _M_X64 ) */