diff --git a/src/Mod/Sketcher/CMakeLists.txt b/src/Mod/Sketcher/CMakeLists.txt
index 740b3ff9ec..041215a194 100644
--- a/src/Mod/Sketcher/CMakeLists.txt
+++ b/src/Mod/Sketcher/CMakeLists.txt
@@ -15,6 +15,7 @@ set(Sketcher_TestScripts
     SketcherTests/__init__.py
     SketcherTests/TestSketchFillet.py
     SketcherTests/TestSketcherSolver.py
+    SketcherTests/TestSketchExpression.py
 )
 
 if(BUILD_GUI)
diff --git a/src/Mod/Sketcher/SketcherTests/TestSketchExpression.py b/src/Mod/Sketcher/SketcherTests/TestSketchExpression.py
new file mode 100644
index 0000000000..6c3c0dc50f
--- /dev/null
+++ b/src/Mod/Sketcher/SketcherTests/TestSketchExpression.py
@@ -0,0 +1,67 @@
+#***************************************************************************
+#*   Copyright (c) 2021 Werner Mayer <werner.wm.mayer@gmx.de>              *
+#*                                                                         *
+#*   This file is part of the FreeCAD CAx development system.              *
+#*                                                                         *
+#*   This program is free software; you can redistribute it and/or modify  *
+#*   it under the terms of the GNU Lesser General Public License (LGPL)    *
+#*   as published by the Free Software Foundation; either version 2 of     *
+#*   the License, or (at your option) any later version.                   *
+#*   for detail see the LICENCE text file.                                 *
+#*                                                                         *
+#*   FreeCAD is distributed in the hope that it will be useful,            *
+#*   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+#*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+#*   GNU Library General Public License for more details.                  *
+#*                                                                         *
+#*   You should have received a copy of the GNU Library General Public     *
+#*   License along with FreeCAD; if not, write to the Free Software        *
+#*   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
+#*   USA                                                                   *
+#***************************************************************************/
+
+
+import math, os, sys, unittest
+import FreeCAD
+import Part
+import Sketcher
+
+App = FreeCAD
+
+class TestSketchExpression(unittest.TestCase):
+    def setUp(self):
+        self.Doc = FreeCAD.newDocument("TestSketchExpr")
+
+    # See https://forum.freecadweb.org/viewtopic.php?f=3&t=64699
+    # and https://forum.freecadweb.org/viewtopic.php?f=10&t=64718
+    def testConstraintWithExpression(self):
+        sketch = self.Doc.addObject('Sketcher::SketchObject','Sketch')
+
+        geoList = []
+        geoList.append(Part.LineSegment(App.Vector(0,5,0),App.Vector(5,5,0)))
+        geoList.append(Part.LineSegment(App.Vector(5,5,0),App.Vector(5,0,0)))
+        geoList.append(Part.LineSegment(App.Vector(5,0,0),App.Vector(0,0,0)))
+        geoList.append(Part.LineSegment(App.Vector(0,0,0),App.Vector(0,5,0)))
+        sketch.addGeometry(geoList,False)
+
+        conList = []
+        conList.append(Sketcher.Constraint('Coincident',0,2,1,1))
+        conList.append(Sketcher.Constraint('Coincident',1,2,2,1))
+        conList.append(Sketcher.Constraint('Coincident',2,2,3,1))
+        conList.append(Sketcher.Constraint('Coincident',3,2,0,1))
+        conList.append(Sketcher.Constraint('Horizontal',0))
+        conList.append(Sketcher.Constraint('Horizontal',2))
+        conList.append(Sketcher.Constraint('Vertical',1))
+        conList.append(Sketcher.Constraint('Vertical',3))
+        sketch.addConstraint(conList)
+        del geoList, conList
+
+        length = sketch.addConstraint(Sketcher.Constraint('Distance',0,6.0)) 
+        height = sketch.addConstraint(Sketcher.Constraint('Distance',3,5.0)) 
+
+        sketch.renameConstraint(length, u'Length')
+        sketch.setExpression('Constraints[{}]'.format(height), u'.Constraints.Length')
+
+    def tearDown(self):
+       # comment out to omit closing document for debugging
+       FreeCAD.closeDocument(self.Doc.Name)
diff --git a/src/Mod/Sketcher/TestSketcherApp.py b/src/Mod/Sketcher/TestSketcherApp.py
index 6a06b1520d..0e62d8d4e0 100644
--- a/src/Mod/Sketcher/TestSketcherApp.py
+++ b/src/Mod/Sketcher/TestSketcherApp.py
@@ -23,6 +23,7 @@
 # Broken-out test modules
 from SketcherTests.TestSketcherSolver import TestSketcherSolver
 from SketcherTests.TestSketchFillet import TestSketchFillet
+from SketcherTests.TestSketchExpression import TestSketchExpression
 
 # Path and PartDesign tests use these functions that used to live here
 # but moved to SketcherTests/TestSketcherSolver.py