diff --git a/lib/hkStubs/Havok/Common/Base/Math/Vector/hkVector4f.h b/lib/hkStubs/Havok/Common/Base/Math/Vector/hkVector4f.h
index bc1014e0..c6b8390f 100644
--- a/lib/hkStubs/Havok/Common/Base/Math/Vector/hkVector4f.h
+++ b/lib/hkStubs/Havok/Common/Base/Math/Vector/hkVector4f.h
@@ -156,6 +156,9 @@ public:
 
     // ========== Misc
 
+    /// Dot product of this vector and (a.x, a.y, a.z, 1).
+    hkSimdFloat32 dot4xyz1(hkVector4fParameter a) const;
+
     // ========== Component access
 
     hkFloat32& operator()(int i) { return reinterpret_cast<float*>(&v)[i]; }
diff --git a/lib/hkStubs/Havok/Common/Base/Math/Vector/hkVector4f.inl b/lib/hkStubs/Havok/Common/Base/Math/Vector/hkVector4f.inl
index e094d5be..853c8ae7 100644
--- a/lib/hkStubs/Havok/Common/Base/Math/Vector/hkVector4f.inl
+++ b/lib/hkStubs/Havok/Common/Base/Math/Vector/hkVector4f.inl
@@ -399,7 +399,8 @@ inline void hkVector4f::_setRotatedDir(hkQuaternionfParameter quat, hkVector4fPa
     setAdd(result, result);
 }
 
-inline void hkVector4f::_setRotatedInverseDir(hkQuaternionfParameter quat, hkVector4fParameter vec) {
+inline void hkVector4f::_setRotatedInverseDir(hkQuaternionfParameter quat,
+                                              hkVector4fParameter vec) {
     const auto& u = quat.getImag();
     const hkSimdFloat32 s = quat.getRealPart();
 
@@ -484,6 +485,20 @@ inline void hkVector4f::normalizeUnsafe() {
     mul(lengthInverseUnsafe<N>());
 }
 
+inline hkSimdFloat32 hkVector4f::dot4xyz1(hkVector4fParameter a) const {
+#ifdef HK_VECTOR4F_AARCH64_NEON
+    float32x4_t x2 = v * a.v;
+    float32x2_t low = vget_low_f32(x2);
+    float32x2_t high = vget_high_f32(x2);
+    high = vset_lane_f32(vgetq_lane_f32(v, 3), high, 1);
+    float32x2_t xy_zw = vpadd_f32(low, high);
+    float32x2_t xyzw = vpadd_f32(xy_zw, xy_zw);
+    return xyzw;
+#else
+    return (v[0] * a.v[0]) + (v[1] * a.v[1]) + (v[2] * a.v[2]) + v[3];
+#endif
+}
+
 template <int Constant>
 inline const hkVector4f& hkVector4f::getConstant() {
     return reinterpret_cast<const hkVector4f&>(g_vectorfConstants[Constant]);