diff --git a/sound/mame/fmopl.c b/sound/mame/fmopl.c
index df2eddb..35da530 100644
--- a/sound/mame/fmopl.c
+++ b/sound/mame/fmopl.c
@@ -1162,7 +1162,7 @@ static int init_tables(void)
 
 	for (x=0; x<TL_RES_LEN; x++)
 	{
-		m = (1<<16) / pow(2, (x+1) * (ENV_STEP/4.0) / 8.0);
+		m = (1<<16) / pow((double)2, (double)(x+1) * (ENV_STEP/4.0) / 8.0);
 		m = floor(m);
 
 		/* we never reach (1<<16) here due to the (x+1) */
diff --git a/sound/mame/ymf262.c b/sound/mame/ymf262.c
index 4c9703f..e96b592 100644
--- a/sound/mame/ymf262.c
+++ b/sound/mame/ymf262.c
@@ -1150,7 +1150,7 @@ static int init_tables(void)
 
 	for (x=0; x<TL_RES_LEN; x++)
 	{
-		m = (1<<16) / pow(2, (x+1) * (ENV_STEP/4.0) / 8.0);
+		m = (1<<16) / pow((double)2, (double)(x+1) * (ENV_STEP/4.0) / 8.0);
 		m = floor(m);
 
 		/* we never reach (1<<16) here due to the (x+1) */
diff --git a/sound/oplgenc.c b/sound/oplgenc.c
index 74b57ab..490929d 100644
--- a/sound/oplgenc.c
+++ b/sound/oplgenc.c
@@ -158,7 +158,7 @@ void oplgen_initialize(UINT rate)
 	}
 	for (i = 0; i < EVC_ENT; i++)
 	{
-		pom = pow(((double)(EVC_ENT - 1 - i) / EVC_ENT), 8) * EVC_ENT;
+		pom = pow(((double)(EVC_ENT - 1 - i) / EVC_ENT), (double)8) * EVC_ENT;
 		oplcfg.envcurve[i] = (SINT32)pom;
 		oplcfg.envcurve[EVC_ENT + i] = i;
 	}