diff --git a/y2017/vision/target_finder.cc b/y2017/vision/target_finder.cc
index e917b2e..640c7fe 100644
--- a/y2017/vision/target_finder.cc
+++ b/y2017/vision/target_finder.cc
@@ -2,8 +2,7 @@
 
 #include <cmath>
 
-namespace y2017 {
-namespace vision {
+namespace y2017::vision {
 
 // Blobs now come in three types:
 //  0) normal blob.
@@ -276,5 +275,4 @@
   *angle = -std::atan2(px, pz);
 }
 
-}  // namespace vision
-}  // namespace y2017
+}  // namespace y2017::vision