diff --git a/src/c3nav/routing/locator.py b/src/c3nav/routing/locator.py
index bbd4d6af..5428c9da 100644
--- a/src/c3nav/routing/locator.py
+++ b/src/c3nav/routing/locator.py
@@ -262,7 +262,7 @@ class Locator:
         # create 2d array with x, y, z, distance as rows
         np_ranges = np.hstack((
             relevant_xyz,
-            np.array(tuple(scan_data[i].distance for i in peer_ids)).reshape((-1, 1)),
+            np.array(tuple(float(scan_data[i].distance) for i in peer_ids)).reshape((-1, 1)),
         ))
 
         #print(np_ranges)