diff --git a/pyproject.toml b/pyproject.toml
index 77385e85..926ca221 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -77,7 +77,7 @@ test = [
     "pytest-cov>=6.0.0",
     "pytest-xdist>=3.6.1",
     "pytest>=8.3.1",
-    "ruff>=0.9.1",
+    "ruff>=0.15.0",
     "pytest-random-order>=1.1.1",
     "pytest-rerunfailures>=15.0",
 ]
diff --git a/src/hssm/distribution_utils/onnx_utils/onnx2pt.py b/src/hssm/distribution_utils/onnx_utils/onnx2pt.py
index 9c04bb33..292b7489 100644
--- a/src/hssm/distribution_utils/onnx_utils/onnx2pt.py
+++ b/src/hssm/distribution_utils/onnx_utils/onnx2pt.py
@@ -29,7 +29,7 @@ def pytensor_gemm(a, b, c=0.0, alpha=1.0, beta=1.0, transA=0, transB=0):  # pyli
 
 
 pt_onnx_ops = {
-    "Add": lambda a, b: onnx_add(a, b),
+    "Add": onnx_add,
     "Constant": lambda value: [value],
     "MatMul": lambda x, y: [pt.dot(x, y)],
     "Relu": lambda x: [pt.math.max(x, 0)],