diff --git a/lib/Renderscript/runtime/rs_cl.c b/lib/Renderscript/runtime/rs_cl.c
index c0543de..b7f9158 100755
--- a/lib/Renderscript/runtime/rs_cl.c
+++ b/lib/Renderscript/runtime/rs_cl.c
@@ -931,7 +931,7 @@
 extern float __attribute__((overloadable)) half_sqrt(float);
 
 extern float __attribute__((overloadable)) fast_length(float v) {
-    return v;
+    return fabs(v);
 }
 extern float __attribute__((overloadable)) fast_length(float2 v) {
     return half_sqrt(v.x*v.x + v.y*v.y);