diff --git a/docs/release-notes/0.13.0.md b/docs/release-notes/0.13.0.md
index dd8a730d..0dcd2b9e 100644
--- a/docs/release-notes/0.13.0.md
+++ b/docs/release-notes/0.13.0.md
@@ -1,4 +1,4 @@
-### 0.13.0 {small}`the-future`
+### 0.13.0 {small}`2025-08-06`
 
 ```{rubric} Features
 ```
@@ -9,6 +9,7 @@
 
 ```{rubric} Performance
 ```
+* speed up `pp.harmony_integrate` for smaller datasets {pr}`421` {smaller}`S Dicks`
 
 ```{rubric} Bug fixes
 ```
diff --git a/src/rapids_singlecell/preprocessing/_harmony/_helper.py b/src/rapids_singlecell/preprocessing/_harmony/_helper.py
index dc663e29..dc3527f7 100644
--- a/src/rapids_singlecell/preprocessing/_harmony/_helper.py
+++ b/src/rapids_singlecell/preprocessing/_harmony/_helper.py
@@ -196,7 +196,7 @@ def _scatter_add_cp_bias_csr(
     n_pcs = X.shape[1]
 
     threads_per_block = 1024
-    if n_cells < 100_000:
+    if n_cells < 300_000:
         blocks = int((n_pcs + 1) / 2)
         scatter_kernel0 = _get_scatter_add_kernel_with_bias_cat0(X.dtype)
         scatter_kernel0(