diff --git a/pyproject.toml b/pyproject.toml
index d6678dc2..bbabc744 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,12 +34,12 @@ dependencies = [
 
 [project.optional-dependencies]
 dev = [
-  "labthings-fastapi[dev]",
   "ruff",
   "mypy[reports]",
   "mypy-gitlab-code-quality",
 #  "pytest-gitlab-code-quality", # pytest version constraint clashes with labthings
   "pytest",
+  "pytest-cov",
   "pytest-mock==3.14",
   "matplotlib~=3.10",
   "hypothesis",
@@ -139,4 +139,4 @@ ignore = [
 [tool.ruff.lint.pydocstyle]
 # This lets the D401 checker understand that decorated thing properties and thing
 # settings act like properties so should be documented as such.
-property-decorators = ["labthings_fastapi.thing_property", "labthings_fastapi.thing_setting"]
\ No newline at end of file
+property-decorators = ["labthings_fastapi.thing_property", "labthings_fastapi.thing_setting"]