diff --git a/engine/sw/d_local.h b/engine/sw/d_local.h
index fe5bf096e..491398952 100644
--- a/engine/sw/d_local.h
+++ b/engine/sw/d_local.h
@@ -125,11 +125,17 @@ extern void (*d_drawspans) (espan_t *pspan);
 #define TRANS_UPPER_CAP (TRANS_MAX / (TRANS_LEVELS + 0.0))
 #define TRANS_LOWER_CAP (1.0 / TRANS_LEVELS)
 
+#ifdef _fastcall
+#define FASTCALL _fastcall
+#else
+#define FASTCALL
+#endif
+
 void D_InitTrans(void);
 // void Set_TransLevelI(int level);
 void D_SetTransLevel(float level, blendmode_t blend);
-extern qbyte _fastcall Trans(qbyte p, qbyte p2);
-extern qbyte _fastcall AddBlend(qbyte p, qbyte p2);
+extern qbyte FASTCALL Trans(qbyte p, qbyte p2);
+extern qbyte FASTCALL AddBlend(qbyte p, qbyte p2);
 
 extern qbyte *pal555to8;
 #endif
diff --git a/engine/sw/d_trans.c b/engine/sw/d_trans.c
index c516a73c5..eea4f4758 100644
--- a/engine/sw/d_trans.c
+++ b/engine/sw/d_trans.c
@@ -31,7 +31,7 @@ void D_InitTrans(void)
 #define Trans(p, p2)	(t_curlookupp[p][p2])
 #else
 // TODO: INLINE THESE FUNCTIONS
-qbyte _fastcall Trans(qbyte p, qbyte p2)
+qbyte FASTCALL Trans(qbyte p, qbyte p2)
 {	
 	int x;
 
@@ -41,7 +41,7 @@ qbyte _fastcall Trans(qbyte p, qbyte p2)
 }
 #endif
 
-qbyte _fastcall AddBlend(qbyte p, qbyte p2)
+qbyte FASTCALL AddBlend(qbyte p, qbyte p2)
 {
 	int x, y;