diff --git a/environment.yml b/environment.yml
index c3c44a4..27ebda4 100644
--- a/environment.yml
+++ b/environment.yml
@@ -5,15 +5,26 @@ channels:
   - nodefaults
 
 dependencies:
+  # core dependencies
   - numpy >=2
   - python >=3.10
-  # testing
+  # testing dependencies
+  - dask
+  - flake8
+  - flask
+  - flask-cors
+  - h5netcdf
   - h5py  # link to same hdf5 lib with netcdf4
+  - moto
   - netcdf4  # has history of broken packages on PyPI
   - pytest
   - pytest-cov
+  - pytest-html
   - pytest-rerunfailures
-  # documentation
+  - pytest-xdist
+  - python-lzf
+  - s3fs >=2025.9.0
+  # documentation dependencies
   - autodocsumm
   - sphinx
   - sphinx_rtd_theme
diff --git a/pyproject.toml b/pyproject.toml
index d198c8d..348b2ef 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -49,19 +49,19 @@ p5dump = "pyfive.p5dump:main"
 
 [project.optional-dependencies]
 test = [
-    "pytest>6.0.0",
-    "pytest-cov>=2.10.1",
-    "pytest-html!=2.1.0",
-    "pytest-rerunfailures",
-    "pytest-xdist",
     "dask",
     "flake8",
     "flask",
     "flask-cors",
     "h5netcdf",
     "h5py",
-    "netCDF4",
     "moto",
+    "netCDF4",
+    "pytest",
+    "pytest-cov",
+    "pytest-html",
+    "pytest-rerunfailures",
+    "pytest-xdist",
     "python-lzf",
     "s3fs>=2025.9.0",  # v-mismatch with boto3 results in ancient s3fs
 ]