diff --git a/pyproject.toml b/pyproject.toml
index 39f33b75..42772142 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -111,6 +111,7 @@ style = [
 ]
 test = [
     "ampform[scipy]",
+    "frozendict",
     "ipywidgets", # symplot
     "nbmake",
     "numpy",
diff --git a/tests/sympy/test_cache.py b/tests/sympy/test_cache.py
index 6e9080f5..0b4b7ee1 100644
--- a/tests/sympy/test_cache.py
+++ b/tests/sympy/test_cache.py
@@ -6,7 +6,7 @@
 import pytest
 import qrules
 import sympy as sp
-from qrules.topology import FrozenDict
+from frozendict import frozendict
 
 from ampform import get_builder
 from ampform.dynamics import EnergyDependentWidth
@@ -100,16 +100,16 @@ def test_amplitude_model(self, expected_hash: str, formalism: SpinFormalism):
 
 class TestFrozenDict:
     def test_qrules_frozen_dict(self):
-        obj: FrozenDict = FrozenDict({})
-        assert get_readable_hash(obj) == "023f1d9cf3576a46b278007d6e5cb0fa"
+        obj: frozendict = frozendict({})
+        assert get_readable_hash(obj) == "c47e813991dc106a9eb228c8aa5f6aa5"
 
-        obj = FrozenDict({"key1": "value1"})
-        assert get_readable_hash(obj) == "076915d85252aa5c87f63702437c6dbd"
+        obj = frozendict({"key1": "value1"})
+        assert get_readable_hash(obj) == "6e8dcf3dc6279354d54d13751fe83f64"
 
-        obj = FrozenDict({
+        obj = frozendict({
             "key1": "value1",
             "key2": 2,
             "key3": (1, 2, 3),
-            "key4": FrozenDict({"nested_key": "nested_value"}),
+            "key4": frozendict({"nested_key": "nested_value"}),
         })
-        assert get_readable_hash(obj) == "c3b3a661e63f57003fc3deea5d23ede9"
+        assert get_readable_hash(obj) == "e6d0016db574753d7578e31812578227"
diff --git a/uv.lock b/uv.lock
index 262115cb..cdcf667e 100644
--- a/uv.lock
+++ b/uv.lock
@@ -70,6 +70,7 @@ viz = [
 dev = [
     { name = "ampform", extra = ["scipy", "viz"] },
     { name = "black" },
+    { name = "frozendict" },
     { name = "ipympl" },
     { name = "ipython", version = "8.18.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
     { name = "ipython", version = "8.30.0", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.10'" },
@@ -166,6 +167,7 @@ style = [
 ]
 test = [
     { name = "ampform", extra = ["scipy"] },
+    { name = "frozendict" },
     { name = "ipywidgets" },
     { name = "nbmake" },
     { name = "numpy", version = "2.0.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
@@ -202,6 +204,7 @@ dev = [
     { name = "ampform", extras = ["scipy"] },
     { name = "ampform", extras = ["scipy", "viz"] },
     { name = "black" },
+    { name = "frozendict" },
     { name = "ipympl" },
     { name = "ipython" },
     { name = "ipywidgets" },
@@ -296,6 +299,7 @@ style = [
 ]
 test = [
     { name = "ampform", extras = ["scipy"] },
+    { name = "frozendict" },
     { name = "ipywidgets" },
     { name = "nbmake" },
     { name = "numpy" },
@@ -1082,6 +1086,33 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/cf/58/8acf1b3e91c58313ce5cb67df61001fc9dcd21be4fadb76c1a2d540e09ed/fqdn-1.5.1-py3-none-any.whl", hash = "sha256:3a179af3761e4df6eb2e026ff9e1a3033d3587bf980a0b1b2e1e5d08d7358014", size = 9121 },
 ]
 
+[[package]]
+name = "frozendict"
+version = "2.4.6"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/bb/59/19eb300ba28e7547538bdf603f1c6c34793240a90e1a7b61b65d8517e35e/frozendict-2.4.6.tar.gz", hash = "sha256:df7cd16470fbd26fc4969a208efadc46319334eb97def1ddf48919b351192b8e", size = 316416 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/a6/7f/e80cdbe0db930b2ba9d46ca35a41b0150156da16dfb79edcc05642690c3b/frozendict-2.4.6-cp310-cp310-macosx_10_9_x86_64.whl", hash = "sha256:c3a05c0a50cab96b4bb0ea25aa752efbfceed5ccb24c007612bc63e51299336f", size = 37927 },
+    { url = "https://files.pythonhosted.org/packages/29/98/27e145ff7e8e63caa95fb8ee4fc56c68acb208bef01a89c3678a66f9a34d/frozendict-2.4.6-cp310-cp310-macosx_11_0_arm64.whl", hash = "sha256:f5b94d5b07c00986f9e37a38dd83c13f5fe3bf3f1ccc8e88edea8fe15d6cd88c", size = 37945 },
+    { url = "https://files.pythonhosted.org/packages/ac/f1/a10be024a9d53441c997b3661ea80ecba6e3130adc53812a4b95b607cdd1/frozendict-2.4.6-cp310-cp310-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:f4c789fd70879ccb6289a603cdebdc4953e7e5dea047d30c1b180529b28257b5", size = 117656 },
+    { url = "https://files.pythonhosted.org/packages/46/a6/34c760975e6f1cb4db59a990d58dcf22287e10241c851804670c74c6a27a/frozendict-2.4.6-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:da6a10164c8a50b34b9ab508a9420df38f4edf286b9ca7b7df8a91767baecb34", size = 117444 },
+    { url = "https://files.pythonhosted.org/packages/62/dd/64bddd1ffa9617f50e7e63656b2a7ad7f0a46c86b5f4a3d2c714d0006277/frozendict-2.4.6-cp310-cp310-musllinux_1_2_aarch64.whl", hash = "sha256:9a8a43036754a941601635ea9c788ebd7a7efbed2becba01b54a887b41b175b9", size = 116801 },
+    { url = "https://files.pythonhosted.org/packages/45/ae/af06a8bde1947277aad895c2f26c3b8b8b6ee9c0c2ad988fb58a9d1dde3f/frozendict-2.4.6-cp310-cp310-musllinux_1_2_x86_64.whl", hash = "sha256:c9905dcf7aa659e6a11b8051114c9fa76dfde3a6e50e6dc129d5aece75b449a2", size = 117329 },
+    { url = "https://files.pythonhosted.org/packages/d2/df/be3fa0457ff661301228f4c59c630699568c8ed9b5480f113b3eea7d0cb3/frozendict-2.4.6-cp310-cp310-win_amd64.whl", hash = "sha256:323f1b674a2cc18f86ab81698e22aba8145d7a755e0ac2cccf142ee2db58620d", size = 37522 },
+    { url = "https://files.pythonhosted.org/packages/4a/6f/c22e0266b4c85f58b4613fec024e040e93753880527bf92b0c1bc228c27c/frozendict-2.4.6-cp310-cp310-win_arm64.whl", hash = "sha256:eabd21d8e5db0c58b60d26b4bb9839cac13132e88277e1376970172a85ee04b3", size = 34056 },
+    { url = "https://files.pythonhosted.org/packages/eb/7e/5d6e86b01742468e5265401529b60d4d24e4b61a751d24473a324da71b55/frozendict-2.4.6-cp39-cp39-macosx_10_9_x86_64.whl", hash = "sha256:a76cee5c4be2a5d1ff063188232fffcce05dde6fd5edd6afe7b75b247526490e", size = 38143 },
+    { url = "https://files.pythonhosted.org/packages/93/d0/3d66be6d154e2bbb4d49445c557f722b248c019b70982654e2440f303671/frozendict-2.4.6-cp39-cp39-macosx_11_0_arm64.whl", hash = "sha256:ba5ef7328706db857a2bdb2c2a17b4cd37c32a19c017cff1bb7eeebc86b0f411", size = 37954 },
+    { url = "https://files.pythonhosted.org/packages/b8/a2/5a178339345edff643240e48dd276581df64b1dd93eaa7d26556396a145b/frozendict-2.4.6-cp39-cp39-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:669237c571856be575eca28a69e92a3d18f8490511eff184937283dc6093bd67", size = 117093 },
+    { url = "https://files.pythonhosted.org/packages/41/df/09a752239eb0661eeda0f34f14577c10edc6f3e4deb7652b3a3efff22ad4/frozendict-2.4.6-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:0aaa11e7c472150efe65adbcd6c17ac0f586896096ab3963775e1c5c58ac0098", size = 116883 },
+    { url = "https://files.pythonhosted.org/packages/22/d4/619d1cfbc74be5641d839a5a2e292f9eac494aa557bfe7c266542c4014a2/frozendict-2.4.6-cp39-cp39-musllinux_1_2_aarch64.whl", hash = "sha256:b8f2829048f29fe115da4a60409be2130e69402e29029339663fac39c90e6e2b", size = 116314 },
+    { url = "https://files.pythonhosted.org/packages/41/b9/40042606a4ac458046ebeecc34cec2971e78e029ea3b6ad4e35833c7f8e6/frozendict-2.4.6-cp39-cp39-musllinux_1_2_x86_64.whl", hash = "sha256:94321e646cc39bebc66954a31edd1847d3a2a3483cf52ff051cd0996e7db07db", size = 117017 },
+    { url = "https://files.pythonhosted.org/packages/e1/6d/e99715f406d8f4297d08b5591365e7d91b39a24cdbaabd3861f95e283c52/frozendict-2.4.6-cp39-cp39-win_amd64.whl", hash = "sha256:74b6b26c15dddfefddeb89813e455b00ebf78d0a3662b89506b4d55c6445a9f4", size = 37815 },
+    { url = "https://files.pythonhosted.org/packages/80/75/cad77ff4bb58277a557becf837345de8f6384d3b1d71f932d22a13223b9e/frozendict-2.4.6-cp39-cp39-win_arm64.whl", hash = "sha256:7088102345d1606450bd1801a61139bbaa2cb0d805b9b692f8d81918ea835da6", size = 34368 },
+    { url = "https://files.pythonhosted.org/packages/04/13/d9839089b900fa7b479cce495d62110cddc4bd5630a04d8469916c0e79c5/frozendict-2.4.6-py311-none-any.whl", hash = "sha256:d065db6a44db2e2375c23eac816f1a022feb2fa98cbb50df44a9e83700accbea", size = 16148 },
+    { url = "https://files.pythonhosted.org/packages/ba/d0/d482c39cee2ab2978a892558cf130681d4574ea208e162da8958b31e9250/frozendict-2.4.6-py312-none-any.whl", hash = "sha256:49344abe90fb75f0f9fdefe6d4ef6d4894e640fadab71f11009d52ad97f370b9", size = 16146 },
+    { url = "https://files.pythonhosted.org/packages/a5/8e/b6bf6a0de482d7d7d7a2aaac8fdc4a4d0bb24a809f5ddd422aa7060eb3d2/frozendict-2.4.6-py313-none-any.whl", hash = "sha256:7134a2bb95d4a16556bb5f2b9736dceb6ea848fa5b6f3f6c2d6dba93b44b4757", size = 16146 },
+]
+
 [[package]]
 name = "gitdb"
 version = "4.0.11"