diff --git a/pyguymer3/geo/fillinSrc/fillin_CoordinateSequence.py b/pyguymer3/geo/fillinSrc/fillin_CoordinateSequence.py
index e076254..bab0988 100644
--- a/pyguymer3/geo/fillinSrc/fillin_CoordinateSequence.py
+++ b/pyguymer3/geo/fillinSrc/fillin_CoordinateSequence.py
@@ -158,6 +158,8 @@ def fillin_CoordinateSequence(coords, fill, /, *, debug = False, eps = 1.0e-12,
                         points1[ipoint + 1, 0],
                         points1[ipoint + 1, 1],
                            debug = debug,
+                             eps = eps,
+                            nmax = nmax,
                           npoint = ns[ipoint] + 1,
                           prefix = prefix,
                         ramLimit = ramLimit,
diff --git a/pyguymer3/geo/great_circle.py b/pyguymer3/geo/great_circle.py
index 1f2f1ce..e21948b 100644
--- a/pyguymer3/geo/great_circle.py
+++ b/pyguymer3/geo/great_circle.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 
 # Define function ...
-def great_circle(lon1, lat1, lon2, lat2, /, *, debug = False, maxdist = None, npoint = None, prefix = ".", ramLimit = 1073741824):
+def great_circle(lon1, lat1, lon2, lat2, /, *, debug = False, eps = 1.0e-12, maxdist = None, nmax = 100, npoint = None, prefix = ".", ramLimit = 1073741824):
     """Calculate the great circle that connects two coordinates.
 
     This function reads in two coordinates (in degrees) on the surface of the
@@ -20,8 +20,12 @@ def great_circle(lon1, lat1, lon2, lat2, /, *, debug = False, maxdist = None, np
         the latitude of the second coordinate (in degrees)
     debug : bool, optional
         print debug messages (in metres)
+    eps : float, optional
+        the tolerance of the Vincenty formula iterations
     maxdist : float, optional
         the maximum distance between points along the great circle
+    nmax : int, optional
+        the maximum number of the Vincenty formula iterations
     npoint : int, optional
         the number of points along the great circle
     prefix : str, optional
@@ -114,6 +118,8 @@ def great_circle(lon1, lat1, lon2, lat2, /, *, debug = False, maxdist = None, np
                     points[ipoint - 1][1],
                     points[ipoint][0],
                     points[ipoint][1],
+                     eps = eps,
+                    nmax = nmax,
                 )                                                               # [m]
 
                 # Check if the distance is too large ...