diff --git a/Cargo.lock b/Cargo.lock
index 78908a489..0328c339d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4237,7 +4237,7 @@ dependencies = [
 [[package]]
 name = "opencadkernel"
 version = "0.1.0"
-source = "git+https://github.com/HakanSeven12/opencadkernel.git?rev=86497ae#86497ae923b7d9297707aaedb712a8678815a238"
+source = "git+https://github.com/ramox81/cadkernel.git?rev=30b3810#30b38101831c454421438acffaa648a53c9d8a2e"
 dependencies = [
  "cavalier_contours",
  "opencadcodec",
@@ -4248,7 +4248,7 @@ dependencies = [
 [[package]]
 name = "opencadkernel-constraints"
 version = "0.1.0"
-source = "git+https://github.com/HakanSeven12/opencadkernel.git?rev=86497ae#86497ae923b7d9297707aaedb712a8678815a238"
+source = "git+https://github.com/ramox81/cadkernel.git?rev=30b3810#30b38101831c454421438acffaa648a53c9d8a2e"
 dependencies = [
  "nalgebra",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 0d21f6f45..c4124e354 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -181,3 +181,7 @@ harness = false
 [[test]]
 name = "integration"
 path = "tests/integration.rs"
+
+[patch."https://github.com/HakanSeven12/opencadkernel.git"]
+opencadkernel = { git = "https://github.com/ramox81/cadkernel.git", rev = "30b3810" }
+opencadkernel-constraints = { git = "https://github.com/ramox81/cadkernel.git", rev = "30b3810" }
diff --git a/src/scene/model/sweep_command_model.rs b/src/scene/model/sweep_command_model.rs
index 7913e22a6..486156ec3 100644
--- a/src/scene/model/sweep_command_model.rs
+++ b/src/scene/model/sweep_command_model.rs
@@ -167,7 +167,11 @@ pub fn sweep_selection_options(profiles: &[EntityType], mut options: SweepOption
     }
     // Spatial profiles keep their own anchor.
     let profiles = profiles.iter().filter(|profile| spatial_profile(profile).is_none()).collect::<Vec<_>>();
-    if profiles.is_empty() {
+    // A single profile takes its base from the path it is swept along
+    // (`sweep_record`).
+    // ponytail: several profiles share the group anchor even when the path
+    // starts inside one of them; the reference rule for that case is unmeasured.
+    if profiles.len() < 2 {
         return Some(options);
     }
     let geometry = profiles.iter().map(|profile| {
@@ -229,10 +233,10 @@ pub fn sweep_record(profile: &EntityType, path: &EntityType, options: SweepOptio
         return Some(record);
     }
     let (sweep_entity, sweep_entity_transform) = embedded_sweep_profile(profile)?;
-    let (plane, wires, _) = kernel::acis::sweep_profile_geometry(&sweep_entity, sweep_entity_transform).ok()?;
+    kernel::acis::sweep_profile_geometry(&sweep_entity, sweep_entity_transform).ok()?;
     let base_point = match options.base_point {
         Some(point) => point.to_array(),
-        None => kernel::brep::sweep_profile_base(plane, &wires)?,
+        None => kernel::acis::sweep_default_base(&sweep_entity, sweep_entity_transform, &embedded_sweep_path(path)?).ok()?,
     };
     let mut base = SolidHistoryNodeBase::new(1);
     base.transform = glam::DMat4::IDENTITY.to_cols_array();