diff --git a/localization/sparse_mapping/build_map.md b/localization/sparse_mapping/build_map.md
index 77610a4b17..8f85d0ad5c 100644
--- a/localization/sparse_mapping/build_map.md
+++ b/localization/sparse_mapping/build_map.md
@@ -362,9 +362,13 @@ be visualized in the ISS as follows:
 
 Open two terminals, and in each one type:
 
-    export BUILD_PATH=$HOME/astrobee/build
+    export BUILD_PATH=$HOME/astrobee
     source $BUILD_PATH/devel/setup.bash
 
+The Astrobee directory above must have ``src`` and ``devel``
+subdirectories, and needs to be adjusted given its location on your
+disk.
+
 In the first terminal start the simulator:
 
     roslaunch astrobee sim.launch speed:=0.75 rviz:=true