diff --git a/v1.3.1/owlps-config/owlps-positioner.conf b/v1.3.1/owlps-config/owlps-positioner.conf
index 94a3d89..0478cbc 100644
--- a/v1.3.1/owlps-config/owlps-positioner.conf
+++ b/v1.3.1/owlps-config/owlps-positioner.conf
@@ -209,6 +209,12 @@ ignore-ap-reference-points = true
 [output]
 # The following options are related to the output of the results.
 
+# Compute the euclidean distance error in two dimensions instead of
+# three dimensions. This can be useful when doing experiments on only
+# one floor.
+# The default is false, i.e. the error is computed in 3D.
+2d-error = true
+
 # This is the default output if none is specified.
 medium = Terminal