diff --git a/src/effects/SkGradientShader.cpp b/src/effects/SkGradientShader.cpp
index 89b9d34..d8ffe5a 100644
--- a/src/effects/SkGradientShader.cpp
+++ b/src/effects/SkGradientShader.cpp
@@ -1816,7 +1816,7 @@
         fStartRadius = SkScalarMul(fRadius1, inv);
         fSr2D2 = SkScalarSquare(fStartRadius);
         fA = SkScalarSquare(fDiff.fX) + SkScalarSquare(fDiff.fY) - SK_Scalar1;
-        fOneOverTwoA = SkScalarInvert(fA * 2);
+        fOneOverTwoA = fA ? SkScalarInvert(fA * 2) : 0;
 
         fPtsToUnit.setTranslate(-fCenter1.fX, -fCenter1.fY);
         fPtsToUnit.postScale(inv, inv);