diff --git a/tools/vio2sf/src/vio2sf/desmume/SPU.cpp b/tools/vio2sf/src/vio2sf/desmume/SPU.cpp
index 8757a3ba6..7e1c3a712 100644
--- a/tools/vio2sf/src/vio2sf/desmume/SPU.cpp
+++ b/tools/vio2sf/src/vio2sf/desmume/SPU.cpp
@@ -529,13 +529,13 @@ static FORCEINLINE s32 Interpolate(SPUInterpolationMode INTERPOLATE_MODE, s32 a,
 		ratio = ratio - sputrunc(ratio);
 		double ratio2 = ((1.0 - cos(ratio * M_PI)) * 0.5);
 		//double ratio2 = (1.0f - cos_lut[((int)(ratio*256.0))&0xFF]) / 2.0f;
-		return (s32)(((1-ratio2)*a) + (ratio2*b));
+		return s32floor((float)(((1-ratio2)*a) + (ratio2*b)));
 	}
 	else
 	{
 		//linear interpolation
 		ratio = ratio - sputrunc(ratio);
-		return s32floor((1-ratio)*a + ratio*b);
+		return s32floor((float)((1-ratio)*a + ratio*b));
 	}
 }