diff --git a/invesalius/constants.py b/invesalius/constants.py
index 71d4c05..d54aa31 100644
--- a/invesalius/constants.py
+++ b/invesalius/constants.py
@@ -659,6 +659,8 @@ BOOLEAN_XOR = 4
 
 MARKER_COLOUR = (1.0, 1.0, 0.)
 MARKER_SIZE = 2
+FIDUCIAL_REGISTRATION_ERROR_THRESHOLD = 3.0
+
 SELECT = 0
 MTC = 1
 FASTRAK = 2
@@ -773,7 +775,7 @@ MTC_PROBE_NAME = "1Probe"
 MTC_REF_NAME = "2Ref"
 MTC_OBJ_NAME = "3Coil"
 
-#OBJECT TRACKING
+# Object tracking
 ARROW_SCALE = 6
 ARROW_UPPER_LIMIT = 15
 #COIL_ANGLES_THRESHOLD = 3 * ARROW_SCALE
diff --git a/invesalius/gui/task_navigator.py b/invesalius/gui/task_navigator.py
index dcd9cc1..279f884 100644
--- a/invesalius/gui/task_navigator.py
+++ b/invesalius/gui/task_navigator.py
@@ -352,7 +352,7 @@ class Navigation():
 
     def GetFiducialRegistrationError(self, icp):
         fre = icp.icp_fre if icp.use_icp else self.fre
-        return fre, fre <= 3
+        return fre, fre <= const.FIDUCIAL_REGISTRATION_ERROR_THRESHOLD
 
     def StartNavigation(self, tracker):
         tracker_fiducials, tracker_fiducials_raw = tracker.GetTrackerFiducials()
--
libgit2 0.21.2