diff --git a/devtools/conda-envs/openeye.yaml b/devtools/conda-envs/openeye.yaml
index 61f75e468..0b932829e 100644
--- a/devtools/conda-envs/openeye.yaml
+++ b/devtools/conda-envs/openeye.yaml
@@ -39,9 +39,9 @@ dependencies:
   - qcengine
   - mdtraj
   - nglview
-  - mypy =1.18
   - typing_extensions
   - pip:
+    - mypy ==2
     - types-setuptools
     - types-toml
     - types-PyYAML
diff --git a/openff/toolkit/topology/molecule.py b/openff/toolkit/topology/molecule.py
index 24097677c..fee8216df 100644
--- a/openff/toolkit/topology/molecule.py
+++ b/openff/toolkit/topology/molecule.py
@@ -5654,7 +5654,7 @@ def _networkx_graph_to_hill_formula(graph: "nx.Graph[int]") -> str:
     if not isinstance(graph, nx.Graph):
         raise ValueError("The graph must be a NetworkX graph.")
 
-    atom_nums: list[int] = [atomic_number for (_, atomic_number) in graph.nodes(data="atomic_number", default=1)]
+    atom_nums: list[int] = [atomic_number for (_, atomic_number) in graph.nodes(data="atomic_number", default=1)]  # type: ignore[misc]
 
     return _atom_nums_to_hill_formula(atom_nums)  # type:ignore[arg-type]
 
diff --git a/pyproject.toml b/pyproject.toml
index 5ba267c84..eac6ca15f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,7 +44,6 @@ lint.isort.known-third-party = [ "openff.interchange", "openff.utilities", "open
 
 [tool.mypy]
 python_version = 3.12
-plugins = "numpy.typing.mypy_plugin"
 warn_unused_configs = true
 # would be nice to flip back to true
 warn_unused_ignores = false