diff --git a/source/blender/blenkernel/intern/curves_geometry.cc b/source/blender/blenkernel/intern/curves_geometry.cc
index aa392951a4d..24b2277126f 100644
--- a/source/blender/blenkernel/intern/curves_geometry.cc
+++ b/source/blender/blenkernel/intern/curves_geometry.cc
@@ -548,23 +548,31 @@ IndexMask CurvesGeometry::nurbs_custom_knot_curves(IndexMaskMemory &memory) cons
 OffsetIndices<int> CurvesGeometry::nurbs_custom_knots_by_curve() const
 {
   const CurvesGeometryRuntime &runtime = *this->runtime;
-  if (this->is_empty()) {
+  if (!this->has_curve_with_type(CURVE_TYPE_NURBS)) {
     return {};
   }
   runtime.custom_knot_offsets_cache.ensure([&](Vector<int> &r_data) {
-    r_data.resize(this->curve_num + 1, 0);
+    r_data.resize(this->curve_num + 1);
 
-    const OffsetIndices points_by_curve = this->points_by_curve();
+    const OffsetIndices<int> points_by_curve = this->points_by_curve();
+    const VArray<int8_t> curve_types = this->curve_types();
     const VArray<int8_t> knot_modes = this->nurbs_knots_modes();
     const VArray<int8_t> orders = this->nurbs_orders();
 
-    int knot_count = 0;
-    for (const int curve : this->curves_range()) {
-      knot_count += knot_modes[curve] == NURBS_KNOT_MODE_CUSTOM ?
-                        points_by_curve[curve].size() + orders[curve] :
-                        0;
-      r_data[curve + 1] = knot_count;
-    }
+    threading::parallel_for(this->curves_range(), 1024, [&](const IndexRange range) {
+      for (const int curve : range) {
+        if (curve_types[curve] != CURVE_TYPE_NURBS) {
+          r_data[curve] = 0;
+          continue;
+        }
+        if (knot_modes[curve] != NURBS_KNOT_MODE_CUSTOM) {
+          r_data[curve] = 0;
+          continue;
+        }
+        r_data[curve] = points_by_curve[curve].size() + orders[curve];
+      }
+    });
+    offset_indices::accumulate_counts_to_offsets(r_data.as_mutable_span());
   });
   return OffsetIndices<int>(runtime.custom_knot_offsets_cache.data());
 }
diff --git a/source/blender/editors/grease_pencil/tests/grease_pencil_merge_test.cc b/source/blender/editors/grease_pencil/tests/grease_pencil_merge_test.cc
index 781b8498771..3fd5c762114 100644
--- a/source/blender/editors/grease_pencil/tests/grease_pencil_merge_test.cc
+++ b/source/blender/editors/grease_pencil/tests/grease_pencil_merge_test.cc
@@ -190,21 +190,28 @@ TEST(grease_pencil_merge, merge_keyframes)
 
   Drawing *drawing = grease_pencil.insert_frame(layer1, 0);
   drawing->strokes_for_write().resize(10, 2);
+  drawing->strokes_for_write().update_curve_types();
 
   drawing = grease_pencil.insert_frame(layer2, 0);
   drawing->strokes_for_write().resize(20, 3);
+  drawing->strokes_for_write().update_curve_types();
   drawing = grease_pencil.insert_frame(layer2, 2);
   drawing->strokes_for_write().resize(30, 4);
+  drawing->strokes_for_write().update_curve_types();
 
   drawing = grease_pencil.insert_frame(layer3, 0);
   drawing->strokes_for_write().resize(40, 5);
+  drawing->strokes_for_write().update_curve_types();
   drawing = grease_pencil.insert_frame(layer3, 3);
   drawing->strokes_for_write().resize(50, 6);
+  drawing->strokes_for_write().update_curve_types();
 
   drawing = grease_pencil.insert_frame(layer4, 1);
   drawing->strokes_for_write().resize(60, 7);
+  drawing->strokes_for_write().update_curve_types();
   drawing = grease_pencil.insert_frame(layer4, 3);
   drawing->strokes_for_write().resize(70, 8);
+  drawing->strokes_for_write().update_curve_types();
 
   GreasePencil *merged_grease_pencil = BKE_grease_pencil_new_nomain();
   BKE_grease_pencil_copy_parameters(grease_pencil, *merged_grease_pencil);
diff --git a/source/blender/geometry/tests/GEO_realize_instances_test.cc b/source/blender/geometry/tests/GEO_realize_instances_test.cc
index 536f393de65..465fb6d3a77 100644
--- a/source/blender/geometry/tests/GEO_realize_instances_test.cc
+++ b/source/blender/geometry/tests/GEO_realize_instances_test.cc
@@ -44,6 +44,7 @@ static void create_test_curves(bke::CurvesGeometry &curves, Span<int> offsets)
 
   curves.resize(points_num, curves_num);
   curves.offsets_for_write().copy_from(offsets);
+  curves.update_curve_types();
 
   /* Attribute storing original indices to test point remapping. */
   SpanAttributeWriter<int> test_indices_writer =