diff --git a/CHANGELOG.md b/CHANGELOG.md
index 52a374dd..8aacf7ac 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@ All notable changes to this project will be documented here.
 
 ## [unreleased]
 
+## [0.25.1] - Aug 5th, 2026
+- The `ConfidenceSlider` toolbox item now also filters `bitmask` annotations
+
 ## [0.25.0] - Aug 5th, 2026
 - Add a `bitmask` annotation mode for raster (per-pixel) segmentation, selectable via `allowed_modes: ["bitmask", ...]`.
   - Painted with the brush (toggle with `toggle_brush_mode_keybind`, default `g`); erase with `toggle_erase_mode_keybind` (default `e`); resize the brush with `increase_brush_size_keybind` / `decrease_brush_size_keybind` (defaults `]` / `[`) or `alt+scroll`. The brush/erase toggles now apply to both `polygon` and `bitmask` modes.
diff --git a/api_spec.md b/api_spec.md
index 53ee150a..9efdab16 100644
--- a/api_spec.md
+++ b/api_spec.md
@@ -484,7 +484,7 @@ This toolbox item requires no configuration and can be added to the `toolbox_ord
 
 ### `confidence_slider_toolbox_item`
 
-The `ConfidenceSlider` toolbox item (added to `toolbox_order` via `AllowedToolboxItem.ConfidenceSlider`) deprecates (hides) or shows spatial annotations based on their confidence values. Unlike the deprecated `KeypointSlider`, it works with **all** spatial annotation types that have a confidence payload (`bbox`, `bbox3`, `polygon`, `polyline`, `contour`, `tbar`, and `point`), across every subtask.
+The `ConfidenceSlider` toolbox item (added to `toolbox_order` via `AllowedToolboxItem.ConfidenceSlider`) deprecates (hides) or shows spatial annotations based on their confidence values. Unlike the deprecated `KeypointSlider`, it works with **all** spatial annotation types that have a confidence payload (`bbox`, `bbox3`, `polygon`, `polyline`, `contour`, `tbar`, `point`, and `bitmask`), across every subtask.
 
 It supports two modes:
 
diff --git a/package-lock.json b/package-lock.json
index 5e9f7648..09f3c256 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "ulabel",
-  "version": "0.25.0",
+  "version": "0.25.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "ulabel",
-      "version": "0.25.0",
+      "version": "0.25.1",
       "license": "MIT",
       "devDependencies": {
         "@eslint/config-inspector": "^1.3.0",
diff --git a/package.json b/package.json
index 0fa6406c..f16f467e 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "ulabel",
   "description": "An image annotation tool.",
-  "version": "0.25.0",
+  "version": "0.25.1",
   "main": "dist/ulabel.min.js",
   "module": "dist/ulabel.min.js",
   "types": "dist/index.d.ts",
diff --git a/src/version.js b/src/version.js
index 1a902fc9..1e78b199 100644
--- a/src/version.js
+++ b/src/version.js
@@ -1 +1 @@
-export const ULABEL_VERSION = "0.25.0";
+export const ULABEL_VERSION = "0.25.1";
diff --git a/tests/annotation_operators.test.js b/tests/annotation_operators.test.js
index f56d2c74..4a6a5cf5 100644
--- a/tests/annotation_operators.test.js
+++ b/tests/annotation_operators.test.js
@@ -44,7 +44,7 @@ describe("get_annotation_confidence_for_class", () => {
 describe("CONFIDENCE_FILTERABLE_SPATIAL_TYPES", () => {
     test("includes the spatial modes and excludes the non-spatial modes", () => {
         expect(CONFIDENCE_FILTERABLE_SPATIAL_TYPES).toEqual(
-            expect.arrayContaining(["contour", "polygon", "polyline", "bbox", "tbar", "bbox3", "point"]),
+            expect.arrayContaining(["contour", "polygon", "polyline", "bbox", "tbar", "bbox3", "point", "bitmask"]),
         );
         expect(CONFIDENCE_FILTERABLE_SPATIAL_TYPES).not.toContain("whole-image");
         expect(CONFIDENCE_FILTERABLE_SPATIAL_TYPES).not.toContain("global");
diff --git a/tests/confidence_slider.test.js b/tests/confidence_slider.test.js
index cfc177ae..43df09fd 100644
--- a/tests/confidence_slider.test.js
+++ b/tests/confidence_slider.test.js
@@ -135,6 +135,22 @@ describe("ConfidenceSlider", () => {
             expect(low.deprecated).toBe(false);
         });
 
+        test("filters bitmask annotations by confidence like any other spatial type", () => {
+            const high_mask = make_annotation("high_mask", "bitmask", [{ class_id: 10, confidence: 0.9 }]);
+            const low_mask = make_annotation("low_mask", "bitmask", [{ class_id: 10, confidence: 0.1 }]);
+            const cs = new ConfidenceSlider(make_ulabel([high_mask, low_mask], {
+                class_filter_mode: "all-only",
+                default_values: { all: 60 },
+                filter_on_load: false,
+            }));
+
+            cs.filter_annotations(false);
+
+            expect(high_mask.deprecated).toBe(false);
+            expect(low_mask.deprecated).toBe(true);
+            expect(low_mask.deprecated_by.confidence_slider).toBe(true);
+        });
+
         test("lowering the threshold un-deprecates previously filtered annotations", () => {
             const low = make_annotation("low", "bbox", [{ class_id: 10, confidence: 0.1 }]);
             const cs = new ConfidenceSlider(make_ulabel([low], {