Index: src/modules/mod_gradient/spiralgradient.cpp
===================================================================
--- src/modules/mod_gradient/spiralgradient.cpp	(revision 364)
+++ src/modules/mod_gradient/spiralgradient.cpp	(working copy)
@@ -151,14 +151,18 @@
 	dist-=floor(dist);
 	if(dist+supersample*0.5>1.0)
 	{
-		Color pool(gradient(dist,supersample*0.5).premult_alpha()*(1.0-(dist-supersample*0.5)));
-		pool+=gradient((dist+supersample*0.5)-1.0,supersample*0.5).premult_alpha()*((dist+supersample*0.5)-1.0);
+		float  left(supersample*0.5-(dist-1.0));
+		float right(supersample*0.5+(dist-1.0));
+		Color pool(gradient(1.0-(left*0.5),left).premult_alpha()*left/supersample);
+		pool+=gradient(right*0.5,right).premult_alpha()*right/supersample;
 		return pool.demult_alpha();
 	}
 	if(dist-supersample*0.5<0.0)
 	{
-		Color pool(gradient(dist,supersample*0.5).premult_alpha()*(dist+supersample*0.5));
-		pool+=gradient(1.0-(dist-supersample*0.5),supersample*0.5).premult_alpha()*(-(dist-supersample*0.5));
+		float  left(supersample*0.5-dist);
+		float right(supersample*0.5+dist);
+		Color pool(gradient(right*0.5,right).premult_alpha()*right/supersample);
+		pool+=gradient(1.0-left*0.5,left).premult_alpha()*left/supersample;
 		return pool.demult_alpha();
 	}