diff --git a/libs/hwui/AmbientShadow.cpp b/libs/hwui/AmbientShadow.cpp
index 2d1cf78..f11437b 100644
--- a/libs/hwui/AmbientShadow.cpp
+++ b/libs/hwui/AmbientShadow.cpp
@@ -128,7 +128,7 @@
 }
 
 inline bool needsExtraForEdge(float firstAlpha, float secondAlpha) {
-    return abs(firstAlpha - secondAlpha) > ALPHA_THRESHOLD;
+    return fabsf(firstAlpha - secondAlpha) > ALPHA_THRESHOLD;
 }
 
 /**