diff --git a/pyproject.toml b/pyproject.toml
index 2f56544..c13c9eb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,23 +5,23 @@ description = "Predictions, counterfactual comparisons, slopes, and hypothesis t
 readme = "README.md"
 requires-python = ">=3.10"
 dependencies = [
-    "duckdb >=1.1.2",
     "narwhals >=1.10.0",
     "numpy >=2.0.0",
     "patsy >=0.5.6",
     "polars >=1.7.0",
-    "pyarrow >=17.0.0",
-    "scipy >=1.14.1",
     "plotnine >=0.13.6",
+    "scipy >=1.14.1",
 ]
 
 [project.optional-dependencies]
 test = [
-    "pandas >=2.2.2",
+    "duckdb >=1.1.2",
     "matplotlib >=3.7.1",
-    "typing-extensions >=4.7.0",
-    "statsmodels >=0.14.0",
+    "pandas >=2.2.2",
+    "pyarrow >=17.0.0",
     "pyfixest >=0.24.2",
+    "statsmodels >=0.14.0",
+    "typing-extensions >=4.7.0",
 ]
 
 [tool.uv]
diff --git a/uv.lock b/uv.lock
index f0dbd29..560594c 100644
--- a/uv.lock
+++ b/uv.lock
@@ -414,20 +414,20 @@ name = "marginaleffects"
 version = "0.0.13.1"
 source = { virtual = "." }
 dependencies = [
-    { name = "duckdb" },
     { name = "narwhals" },
     { name = "numpy" },
     { name = "patsy" },
     { name = "plotnine" },
     { name = "polars" },
-    { name = "pyarrow" },
     { name = "scipy" },
 ]
 
 [package.optional-dependencies]
 test = [
+    { name = "duckdb" },
     { name = "matplotlib" },
     { name = "pandas" },
+    { name = "pyarrow" },
     { name = "pyfixest" },
     { name = "statsmodels" },
     { name = "typing-extensions" },
@@ -442,7 +442,7 @@ dev = [
 
 [package.metadata]
 requires-dist = [
-    { name = "duckdb" },
+    { name = "duckdb", marker = "extra == 'test'", specifier = ">=1.1.2" },
     { name = "matplotlib", marker = "extra == 'test'", specifier = ">=3.7.1" },
     { name = "narwhals", specifier = ">=1.10.0" },
     { name = "numpy", specifier = ">=2.0.0" },
@@ -450,7 +450,7 @@ requires-dist = [
     { name = "patsy", specifier = ">=0.5.6" },
     { name = "plotnine", specifier = ">=0.13.6" },
     { name = "polars", specifier = ">=1.7.0" },
-    { name = "pyarrow", specifier = ">=17.0.0" },
+    { name = "pyarrow", marker = "extra == 'test'", specifier = ">=17.0.0" },
     { name = "pyfixest", marker = "extra == 'test'", specifier = ">=0.24.2" },
     { name = "scipy", specifier = ">=1.14.1" },
     { name = "statsmodels", marker = "extra == 'test'", specifier = ">=0.14.0" },