diff --git a/pyproject.toml b/pyproject.toml
index 1104785e..d39a171d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -62,6 +62,7 @@ tinker = [
     "huggingface_hub",
     "numpy",
     "pillow",
+    "pyarrow>=15.0.0",
     "pydantic>=2.12.5",
     "tinker>=0.8.1",
     "torch>=2.8.0",
diff --git a/uv.lock b/uv.lock
index 8a2a7880..5122fb56 100644
--- a/uv.lock
+++ b/uv.lock
@@ -5400,6 +5400,7 @@ tinker = [
     { name = "huggingface-hub" },
     { name = "numpy" },
     { name = "pillow" },
+    { name = "pyarrow" },
     { name = "pydantic" },
     { name = "tinker" },
     { name = "torch", version = "2.9.1", source = { registry = "https://pypi.org/simple" }, marker = "sys_platform != 'linux'" },
@@ -5456,6 +5457,7 @@ requires-dist = [
     { name = "pillow", marker = "extra == 'tinker'" },
     { name = "polars", specifier = ">=1.26.0" },
     { name = "pyarrow", marker = "extra == 'backend'", specifier = ">=15.0.0" },
+    { name = "pyarrow", marker = "extra == 'tinker'", specifier = ">=15.0.0" },
     { name = "pydantic", marker = "extra == 'tinker'", specifier = ">=2.12.5" },
     { name = "pytest", marker = "extra == 'backend'", specifier = ">=8.4.1" },
     { name = "seaborn", marker = "extra == 'plotting'", specifier = ">=0.13.2" },