diff --git a/Cargo.lock b/Cargo.lock
index 2927210c5b..e8026b43e3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4054,7 +4054,7 @@ dependencies = [
 [[package]]
 name = "solidcore"
 version = "1.0.1"
-source = "git+https://github.com/tangency-labs/solidcore?rev=de85a3e006924bda0d83d6b1cae19ec30e0b3c6b#de85a3e006924bda0d83d6b1cae19ec30e0b3c6b"
+source = "git+https://github.com/tangency-labs/solidcore?rev=c931c96411015f97f93ad392db1d99faa8b9cdca#c931c96411015f97f93ad392db1d99faa8b9cdca"
 dependencies = [
  "thiserror 2.0.21",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 425c5406bf..5f38efcbf3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,7 +35,7 @@ solidcraft-3dx-client = { path = "crates/threedx-client" }
 # they reach parity (crates/smlib/src/route.rs). Pinned; move the rev on its own commit. For a
 # local checkout, add `[patch."https://github.com/tangency-labs/solidcore"] solidcore = { path =
 # "../solidcore/crates/solidcore" }` to a `.cargo/config.toml` outside the repository.
-solidcore = { git = "https://github.com/tangency-labs/solidcore", rev = "de85a3e006924bda0d83d6b1cae19ec30e0b3c6b" }
+solidcore = { git = "https://github.com/tangency-labs/solidcore", rev = "c931c96411015f97f93ad392db1d99faa8b9cdca" }
 
 # foundation
 thiserror = "2"
diff --git a/crates/smlib/src/core/split.rs b/crates/smlib/src/core/split.rs
index 738a71cf09..f39044404d 100644
--- a/crates/smlib/src/core/split.rs
+++ b/crates/smlib/src/core/split.rs
@@ -499,7 +499,9 @@ pub(crate) fn split_body_by_sheet(body: &Body, sheet: &Body, face: usize) -> Res
                 brep_copy(k, &g)?
             };
             let Some(&f) = brep_p1::faces(&copy, None)?.get(face) else { return Ok(Err(Error::Argument)) };
-            let turned = orient_sheet_surfaces(k, &mut copy, Some(f), !flip);
+            // The UV swaps notify as SMLib's objects do: through the kernel's callbacks, with
+            // the sheet's own attributes, so its faces' tags see each swap.
+            let turned = with_kernel_callbacks(k, &mut copy, |k, b, env| orient_sheet_surfaces(k, b, Some(f), !flip, env));
             copy.refresh_cached_topology();
             Ok(match turned {
                 Ok(()) => Ok(copy),