diff --git a/.gitignore b/.gitignore
index bc9f191464..032783fb59 100644
--- a/.gitignore
+++ b/.gitignore
@@ -35,7 +35,7 @@
 /resources/mozilla-ca-certs.pem
 /resources/user-agent-data.json
 /resources/piper-voices.json
-/icons/icns/*.iconset
+/icons/icns/*/*.iconset
 /setup/installer/windows/calibre/build.log
 /setup/pyqt_enums
 /tags
diff --git a/bypy/macos.conf b/bypy/macos.conf
index 4d79529b72..467cbb656c 100644
--- a/bypy/macos.conf
+++ b/bypy/macos.conf
@@ -1,5 +1,5 @@
 # Requires installation of XCode 16.2 and
-# python3 -m pip install certifi html5lib
+# python3 -m pip install certifi html5lib icnsutil
 
 vm_name 'macos-calibre'
 root '/Users/Shared/calibre-build'
diff --git a/bypy/macos/__main__.py b/bypy/macos/__main__.py
index fe419175e5..502fcfe461 100644
--- a/bypy/macos/__main__.py
+++ b/bypy/macos/__main__.py
@@ -19,6 +19,8 @@ import zipfile
 from functools import partial, reduce
 from itertools import repeat
 
+import icnsutil
+
 from bypy.constants import OUTPUT_DIR, PREFIX, PYTHON, python_major_minor_version
 from bypy.constants import SRC as CALIBRE_DIR
 from bypy.freeze import extract_extension_modules, fix_pycryptodome, freeze_python, is_package_dir, path_to_freeze_dir
@@ -49,6 +51,20 @@ EXPECTED_ARCHES = {'x86_64', 'arm64'}
 MINIMUM_SYSTEM_VERSION = '14.0.0'
 
 
+def generate_icns(light_iconset: str, dark_iconset: str, output_path: str) -> None:
+    def add_iconset(icns, path):
+        for img in os.listdir(path):
+            if img.endswith('.png'):
+                icns.add_media(file=os.path.join(path, img))
+    dark_icns = icnsutil.IcnsFile()
+    add_iconset(dark_icns, dark_iconset)
+    dark_icns.write(output_path, toc=True)
+    light_icns = icnsutil.IcnsFile()
+    add_iconset(light_icns, light_iconset)
+    light_icns.add_media(icnsutil.IcnsType.key_from_readable('dark'), file=output_path)
+    light_icns.write(output_path, toc=True)
+
+
 def compile_launcher_lib(contents_dir, base, pyver, inc_dir):
     print('\tCompiling calibre_launcher.dylib')
     env, env_vals = [], []
@@ -223,6 +239,7 @@ class Freeze:
 
     @flush
     def run_tests(self):
+        print('Running tests...', flush=True)
         self.test_runner(join(self.contents_dir, 'MacOS', 'calibre-debug'), self.contents_dir)
 
     @flush
@@ -377,9 +394,10 @@ class Freeze:
         if not icons:
             raise SystemExit('Failed to find icns format icons')
         for x in icons:
-            subprocess.check_call([
-                'iconutil', '-c', 'icns', x, '-o', join(
-                    self.resources_dir, basename(x).partition('.')[0] + '.icns')])
+            output_icns = join(self.resources_dir, basename(x).partition('.')[0] + '.icns')
+            xd = x.replace('/light/', '/dark/')
+            assert x != xd
+            generate_icns(x, xd, output_icns)
         for helpers in (self.helpers_dir,):
             os.makedirs(helpers)
             cdir = dirname(helpers)
diff --git a/icons/icns/make_iconsets.py b/icons/icns/make_iconsets.py
index 48b9dc1974..45ee5db9c8 100755
--- a/icons/icns/make_iconsets.py
+++ b/icons/icns/make_iconsets.py
@@ -41,12 +41,11 @@ with tempfile.TemporaryDirectory() as tdir:
         frame = render_frame(mode, sz)
         icon = os.path.join(tdir, f'icon-{sz}.png')
         render_svg(src, int(shrink_factor * sz), icon)
-        subprocess.check_call(f'convert {frame} {icon} -gravity center -compose over -composite {iname}'.split())
+        subprocess.check_call(f'magick {frame} {icon} -gravity center -compose over -composite {iname}'.split())
 
     for mode in ('light', 'dark'):
         subdir = mode
-        if not os.path.exists(subdir):
-            os.mkdir(subdir)
+        os.makedirs(subdir, exist_ok=True)
         for name, src in sources.items():
             iconset = j(subdir, name + '.iconset')
             if os.path.exists(iconset):
@@ -54,19 +53,19 @@ with tempfile.TemporaryDirectory() as tdir:
             os.mkdir(iconset)
             os.chdir(iconset)
             try:
-                for sz in (16, 32, 128, 256, 512, 1024):
+                for sz in (16, 32, 64, 128, 256, 512, 1024):
                     iname = f'icon_{sz}x{sz}.png'
                     iname2x = f'icon_{sz // 2}x{sz // 2}@2x.png'
                     if sz < 128:
                         render_svg(src, sz, iname)
                     else:
                         render_framed(mode, sz, iname)
+                    subprocess.check_call(['optipng', '-o7', '-strip', 'all', iname])
                     if sz > 16:
                         shutil.copy2(iname, iname2x)
-                    if sz > 512:
+                    if sz > 512 or sz == 64:
                         os.remove(iname)
-                    for name in (iname, iname2x):
-                        if os.path.exists(name):
-                            subprocess.check_call(['optipng', '-o7', '-strip', 'all', name])
+                    if sz == 128:
+                        os.remove(iname2x)
             finally:
                 os.chdir('../..')