diff --git a/src/bin/minitracer/trace.wgsl b/src/bin/minitracer/trace.wgsl
index 57b1fb7..3a5352e 100644
--- a/src/bin/minitracer/trace.wgsl
+++ b/src/bin/minitracer/trace.wgsl
@@ -127,12 +127,12 @@ fn rand_float() -> f32 {
 }
 
 fn rand_sphere() -> vec3f {
-	loop {
+	for (var k = 0; k < 16; k++) {
 		let v = vec3f(rand_float(), rand_float(), rand_float()) - 0.5;
 		let l = length(v);
 		if (length(v) <= 0.5) {
 			return v / l;
 		}
 	}
-	return vec3f(0.0); // unreachable
+	return vec3f(0.0); // safeguard
 }