diff --git a/cadquery/assembly.py b/cadquery/assembly.py
index b0233dad..cfe3537c 100644
--- a/cadquery/assembly.py
+++ b/cadquery/assembly.py
@@ -14,7 +14,7 @@ from .occ_impl.solver import (
 )
 from .occ_impl.exporters.assembly import exportAssembly, exportCAF
 
-from .selectors import _grammar as _selector_grammar
+from .selectors import _expression_grammar as _selector_grammar
 
 # type definitions
 AssemblyObjects = Union[Shape, Workplane, None]
diff --git a/tests/test_assembly.py b/tests/test_assembly.py
index 16d2897b..f88c23c8 100644
--- a/tests/test_assembly.py
+++ b/tests/test_assembly.py
@@ -218,3 +218,10 @@ def test_empty_solve(nested_assy):
 
     with pytest.raises(ValueError):
         nested_assy.solve()
+
+
+def test_expression_grammar(nested_assy):
+
+    nested_assy.constrain(
+        "TOP@faces@>Z", "SECOND/BOTTOM@vertices@>X and >Y and >Z", "Point"
+    )