diff --git a/poetry.lock b/poetry.lock
index 7063af60..d6972d8a 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 1.7.1 and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.8.2 and should not be changed by hand.
 
 [[package]]
 name = "attrs"
@@ -431,13 +431,13 @@ testing = ["argcomplete", "attrs (>=19.2.0)", "hypothesis (>=3.56)", "mock", "no
 
 [[package]]
 name = "pytest-cov"
-version = "4.1.0"
+version = "5.0.0"
 description = "Pytest plugin for measuring coverage."
 optional = false
-python-versions = ">=3.7"
+python-versions = ">=3.8"
 files = [
-    {file = "pytest-cov-4.1.0.tar.gz", hash = "sha256:3904b13dfbfec47f003b8e77fd5b589cd11904a21ddf1ab38a64f204d6a10ef6"},
-    {file = "pytest_cov-4.1.0-py3-none-any.whl", hash = "sha256:6ba70b9e97e69fcc3fb45bfeab2d0a138fb65c4d0d6a41ef33983ad114be8c3a"},
+    {file = "pytest-cov-5.0.0.tar.gz", hash = "sha256:5837b58e9f6ebd335b0f8060eecce69b662415b16dc503883a02f45dfeb14857"},
+    {file = "pytest_cov-5.0.0-py3-none-any.whl", hash = "sha256:4f0764a1219df53214206bf1feea4633c3b558a2925c8b59f144f682861ce652"},
 ]
 
 [package.dependencies]
@@ -445,7 +445,7 @@ coverage = {version = ">=5.2.1", extras = ["toml"]}
 pytest = ">=4.6"
 
 [package.extras]
-testing = ["fields", "hunter", "process-tests", "pytest-xdist", "six", "virtualenv"]
+testing = ["fields", "hunter", "process-tests", "pytest-xdist", "virtualenv"]
 
 [[package]]
 name = "pytket"
@@ -645,4 +645,4 @@ files = [
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.10"
-content-hash = "a617a53ba3d091a7264008eec3fe5ef320958014f532af1fd90a021fbc751a90"
+content-hash = "aa6896141d541fc44b7d28b6b98b4eb42472f8e7409f3ec73cb527efa81c6446"
diff --git a/pyproject.toml b/pyproject.toml
index 9c6421f0..aab85711 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,7 +18,7 @@ python = ">=3.10"
 maturin = "^1.3.0"
 pytket = "*"
 pytest = "^7.1.2"
-pytest-cov = "^4.1.0"
+pytest-cov = "^5.0.0"
 ruff = "^0.1.3"
 hypothesis = "^6.91.1"