diff --git a/cadquery/occ_impl/shapes.py b/cadquery/occ_impl/shapes.py
index 540729da2..49f2ab667 100644
--- a/cadquery/occ_impl/shapes.py
+++ b/cadquery/occ_impl/shapes.py
@@ -357,14 +357,14 @@
 inverse_shape_LUT = {v: k for k, v in shape_LUT.items()}
 
 downcast_LUT = {
-    ta.TopAbs_VERTEX: TopoDS.Vertex_s,
-    ta.TopAbs_EDGE: TopoDS.Edge_s,
-    ta.TopAbs_WIRE: TopoDS.Wire_s,
-    ta.TopAbs_FACE: TopoDS.Face_s,
-    ta.TopAbs_SHELL: TopoDS.Shell_s,
-    ta.TopAbs_SOLID: TopoDS.Solid_s,
-    ta.TopAbs_COMPSOLID: TopoDS.CompSolid_s,
-    ta.TopAbs_COMPOUND: TopoDS.Compound_s,
+    ta.TopAbs_VERTEX: TopoDS.Vertex,
+    ta.TopAbs_EDGE: TopoDS.Edge,
+    ta.TopAbs_WIRE: TopoDS.Wire,
+    ta.TopAbs_FACE: TopoDS.Face,
+    ta.TopAbs_SHELL: TopoDS.Shell,
+    ta.TopAbs_SOLID: TopoDS.Solid,
+    ta.TopAbs_COMPSOLID: TopoDS.CompSolid,
+    ta.TopAbs_COMPOUND: TopoDS.Compound,
 }
 
 geom_LUT = {
@@ -895,7 +895,7 @@ def Edges(self) -> List["Edge"]:
         return [
             Edge(i)
             for i in self._entities("Edge")
-            if not BRep_Tool.Degenerated_s(TopoDS.Edge_s(i))
+            if not BRep_Tool.Degenerated_s(TopoDS.Edge(i))
         ]
 
     def Compounds(self) -> List["Compound"]:
@@ -2902,8 +2902,8 @@ def stitch(self, other: "Wire") -> "Wire":
         """Attempt to stitch wires"""
 
         wire_builder = BRepBuilderAPI_MakeWire()
-        wire_builder.Add(TopoDS.Wire_s(self.wrapped))
-        wire_builder.Add(TopoDS.Wire_s(other.wrapped))
+        wire_builder.Add(TopoDS.Wire(self.wrapped))
+        wire_builder.Add(TopoDS.Wire(other.wrapped))
         wire_builder.Build()
 
         return self.__class__(wire_builder.Wire())
@@ -3398,7 +3398,7 @@ def makeFromWires(cls, outerWire: Wire, innerWires: List[Wire] = []) -> "Face":
         # fix outer wire
         sf_s = ShapeFix_Shape(outerWire.wrapped)
         sf_s.Perform()
-        wo = TopoDS.Wire_s(sf_s.Shape())
+        wo = TopoDS.Wire(sf_s.Shape())
 
         face_builder = BRepBuilderAPI_MakeFace(wo, True)
 
@@ -3490,7 +3490,7 @@ def chamfer2D(self, d: float, vertices: Iterable[Vertex]) -> "Face":
             e1, e2 = edges
 
             chamfer_builder.AddChamfer(
-                TopoDS.Edge_s(e1.wrapped), TopoDS.Edge_s(e2.wrapped), d, d
+                tcast(TopoDS_Edge, e1.wrapped), tcast(TopoDS_Edge, e2.wrapped), d, d
             )
 
         chamfer_builder.Build()
@@ -3612,7 +3612,7 @@ def trim(self, outer: Wire, *inner: Wire) -> Self:
         bldr = BRepBuilderAPI_MakeFace(self._geomAdaptor(), outer.wrapped)
 
         for w in inner:
-            bldr.Add(TopoDS.Wire_s(w.wrapped))
+            bldr.Add(TopoDS.Wire(w.wrapped))
 
         return self.__class__(bldr.Face()).fix()
 
@@ -3679,9 +3679,7 @@ def addHole(self, *inner: Wire | Edge) -> Self:
         bldr = BRepBuilderAPI_MakeFace(self.wrapped)
 
         for w in inner:
-            bldr.Add(
-                TopoDS.Wire_s(w.wrapped if isinstance(w, Wire) else wire(w).wrapped)
-            )
+            bldr.Add(TopoDS.Wire(w.wrapped if isinstance(w, Wire) else wire(w).wrapped))
 
         return self.__class__(bldr.Face()).fix()
 
@@ -3763,7 +3761,7 @@ def chamfer(
         for e in nativeEdges:
             face = edge_face_map.FindFromKey(e).First()
             chamfer_builder.Add(
-                d1, d2, e, TopoDS.Face_s(face)
+                d1, d2, e, TopoDS.Face(face)
             )  # NB: edge_face_map return a generic TopoDS_Shape
         return self.__class__(chamfer_builder.Shape())
 
@@ -6107,7 +6105,7 @@ def cap(
 
     for e in _get_edges(s):
         f = _get_one(e.ancestors(ctx, "Face"), "Face")
-        builder.Add(e.wrapped, f.wrapped, GeomAbs_G2, True)
+        builder.Add(e.wrapped, f.wrapped, GeomAbs_Shape.GeomAbs_G1, True)
 
     for c in constraints:
         if isinstance(c, Shape):
diff --git a/conda/meta.yaml b/conda/meta.yaml
index 68761b45c..561dc7061 100644
--- a/conda/meta.yaml
+++ b/conda/meta.yaml
@@ -16,8 +16,7 @@ requirements:
     - setuptools
   run:
     - python >=3.10
-    - ocp=7.8.1
-    - vtk=*=qt*
+    - ocp=7.9.3.1
     - pyparsing >=3.0.0
     - ezdxf>=1.3.0
     - ipython
diff --git a/environment.yml b/environment.yml
index 590179b13..927b056bc 100644
--- a/environment.yml
+++ b/environment.yml
@@ -4,8 +4,8 @@ channels:
 dependencies:
   - python>=3.10
   - ipython
-  - ocp=7.8.1
-  - vtk=*=qt*
+# - cadquery/label/dev::ocp=x.x.x for dev
+  - ocp=7.9.3.1 
   - pyparsing>=3.0.0
   - sphinx=9.1.0
 #  - sphinx_rtd_theme=3.1.0
diff --git a/setup.py b/setup.py
index 2bcbf98fd..17667cf42 100644
--- a/setup.py
+++ b/setup.py
@@ -26,7 +26,7 @@
 # Only include the installation dependencies if we are not running on RTD or AppVeyor or in a conda env
 if not is_rtd and not is_appveyor and not is_azure and not is_conda:
     reqs = [
-        "cadquery-ocp>=7.8.1,<7.9",
+        "cadquery-ocp>=7.9.3.1,<8.0",
         "ezdxf>=1.3.0",
         "multimethod>=1.11,<2.0",
         "nlopt>=2.9.0,<3.0",