diff --git a/app/pdb/vectors-cmds.c b/app/pdb/vectors-cmds.c
index 2b01b78f4d3bfa2367f29840006f6f2de68ac579..8d1314c40a4780965992191046acdbd70a6e2752 100644
--- a/app/pdb/vectors-cmds.c
+++ b/app/pdb/vectors-cmds.c
@@ -1499,8 +1499,8 @@ register_vectors_procs (GimpPDB *pdb)
   gimp_procedure_add_argument (procedure,
                                g_param_spec_double ("precision",
                                                     "precision",
-                                                    "The precision used for the approximation",
-                                                    -G_MAXDOUBLE, G_MAXDOUBLE, 0,
+                                                    "The precision used for approximating straight portions of the stroke",
+                                                    0.0, G_MAXDOUBLE, 0.1,
                                                     GIMP_PARAM_READWRITE));
   gimp_procedure_add_return_value (procedure,
                                    g_param_spec_double ("length",
diff --git a/libgimp/gimpvectors_pdb.c b/libgimp/gimpvectors_pdb.c
index 95b9abc6297c8bc310743b17e9431661450ce9ce..51fa5fe3c2bcda72342ce1554d6f331670a5e307 100644
--- a/libgimp/gimpvectors_pdb.c
+++ b/libgimp/gimpvectors_pdb.c
@@ -202,7 +202,7 @@ gimp_vectors_get_strokes (GimpVectors *vectors,
  * gimp_vectors_stroke_get_length:
  * @vectors: The vectors object.
  * @stroke_id: The stroke ID.
- * @precision: The precision used for the approximation.
+ * @precision: The precision used for approximating straight portions of the stroke.
  *
  * Measure the length of the given stroke.
  *
diff --git a/pdb/groups/vectors.pdb b/pdb/groups/vectors.pdb
index 280dd6bfdc3af275e4fdee528da8bbb4fe7dd983..73c394567d71097d1d56c1a37355e34d90a9c124 100644
--- a/pdb/groups/vectors.pdb
+++ b/pdb/groups/vectors.pdb
@@ -179,8 +179,8 @@ sub vectors_stroke_get_length {
 	  desc => 'The vectors object' },
 	{ name => 'stroke_id', type => 'int32',
 	  desc => 'The stroke ID' },
-        { name => 'precision', type => 'float',
-          desc => 'The precision used for the approximation' }
+        { name => 'precision', type => '0.0 <= float', default => 0.1,
+          desc => 'The precision used for approximating straight portions of the stroke' }
     );
 
     @outargs = (