diff --git a/Alc/ALu.c b/Alc/ALu.c
index 76a987aa..6c474f23 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -779,7 +779,7 @@ ALvoid CalcSourceParams(ALsource *ALSource, const ALCcontext *ALContext)
         DirGain = aluSqrt(Position[0]*Position[0] + Position[2]*Position[2]);
         // elevation adjustment for directional gain. this sucks, but
         // has low complexity
-        AmbientGain = aluSqrt(1.0/Device->NumChan);
+        AmbientGain = aluSqrt(1.0f/Device->NumChan);
         for(i = 0;i < MAXCHANNELS;i++)
         {
             ALuint i2;