diff --git a/Package.swift b/Package.swift
index 05cf5b6..ab3b461 100644
--- a/Package.swift
+++ b/Package.swift
@@ -35,7 +35,7 @@ let package = Package(
         ),
     ],
     dependencies: [
-        occtDep("OCCTSwift", from: "1.11.3"),   // ≥1.11.3: robust importers split multibody files (#302); allEdgePolylinesIndexed since 1.10.0 (#275)
+        occtDep("OCCTSwift", from: "1.12.3"),   // ≥1.12.3: thread-safe 3D fillet/chamfer (#298); multibody importers (#302); allEdgePolylinesIndexed (#275)
         occtDep("OCCTSwiftViewport", from: "1.1.23"),
         occtDep("OCCTSwiftIO", from: "1.7.0"),  // ≥1.7.0: ShapeLoader splits multibody into per-body entries (#21)
     ],
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index ef3c9bf..2e30175 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 Most recent first. Pre-1.0 was free to break; SemVer-stable from v1.0.0 per the [cohort SemVer policy](https://github.com/gsdali/OCCTSwift/blob/main/docs/SEMVER.md).
 
+## v1.4.1 — 2026-07-18
+
+**Repin OCCTSwift floor to 1.12.3.** OCCTSwift v1.12.3 carries OCCT kernel patch 0003, making 3D fillet/chamfer reentrant across threads ([OCCTSwift#298](https://github.com/SecondMouseAU/OCCTSwift/issues/298) / upstream [OCCT#1374](https://github.com/Open-Cascade-SAS/OCCT/pull/1374)) — concurrent fillet builds no longer corrupt each other into wrong-but-plausible solids. Ecosystem-wide floor bump; no API or behaviour change.
+
 ## v1.4.0 — 2026-07-18
 
 **The robust STL/IGES reload splits a multibody file into one `ViewportBody` per body.** Closes [#36](https://github.com/SecondMouseAU/OCCTSwiftTools/issues/36).