diff --git a/src/ChFi3d/ChFi3d_Builder_6.cxx b/src/ChFi3d/ChFi3d_Builder_6.cxx
index 50a9233720..566af9e52c 100755
--- a/src/ChFi3d/ChFi3d_Builder_6.cxx
+++ b/src/ChFi3d/ChFi3d_Builder_6.cxx
@@ -538,7 +538,7 @@ Standard_Boolean ChFi3d_Builder::CompleteData
   Handle(BRepBlend_AppFunc) TheFunc 
     = new (BRepBlend_AppFunc)(lin, Func, tolapp3d, 1.e-5);
 
-  Standard_Integer Degmax = 20, Segmax = 100;
+  Standard_Integer Degmax = 20, Segmax = 5000;
   BRepBlend_AppSurface approx (TheFunc, 
 			       lin->Point(1).Parameter(),
 			       lin->Point(lin->NbPoints()).Parameter(),
diff --git a/tests/bugs/modalg/bug23651_1 b/tests/bugs/modalg/bug23651_1
new file mode 100755
index 0000000000..84593c5053
--- /dev/null
+++ b/tests/bugs/modalg/bug23651_1
@@ -0,0 +1,13 @@
+puts "============"
+puts "CR23651"
+puts "============"
+puts ""
+###############################
+## Exception on fillet construction between NURBS and surface of revolution
+###############################
+
+restore [locate_data_file bug23651_turbine_shell_one_edge.brep] s
+explode s e
+blend result s 1 s_4
+
+set 3dviewer 1
diff --git a/tests/bugs/modalg/bug23651_2 b/tests/bugs/modalg/bug23651_2
new file mode 100755
index 0000000000..2c4fa32649
--- /dev/null
+++ b/tests/bugs/modalg/bug23651_2
@@ -0,0 +1,16 @@
+puts "============"
+puts "CR23651"
+puts "============"
+puts ""
+###############################
+## Exception on fillet construction between NURBS and surface of revolution
+###############################
+
+restore [locate_data_file bug23651_turbine_shell_one_edge.brep ] a
+explode a e
+
+mkevol result a
+updatevol a_4 0. 1.5 0.05 1 0.45 1 0.5 1.5 0.55 2 0.95 2 1. 1.5
+buildevol
+
+set 3dviewer 1