diff --git a/python/ribasim/ribasim/input_base.py b/python/ribasim/ribasim/input_base.py
index c6613c908..48e0e03fd 100644
--- a/python/ribasim/ribasim/input_base.py
+++ b/python/ribasim/ribasim/input_base.py
@@ -217,7 +217,6 @@ def _check_dataframe(cls, value: Any) -> Any:
 
         # Enable initialization with a DataFrame.
         if isinstance(value, pd.DataFrame | gpd.GeoDataFrame):
-            value.index.rename("fid", inplace=True)
             value = {"df": value}
 
         return value
@@ -386,7 +385,6 @@ def _from_db(cls, path: Path, table: str):
                     # tell pyarrow to map to pd.ArrowDtype rather than NumPy
                     arrow_to_pandas_kwargs={"types_mapper": pd.ArrowDtype},
                 )
-                df.index.rename(cls.tableschema()._index_name(), inplace=True)
             else:
                 df = None
 
diff --git a/python/ribasim/ribasim/schemas.py b/python/ribasim/ribasim/schemas.py
index 2bcd22222..ac0292ccb 100644
--- a/python/ribasim/ribasim/schemas.py
+++ b/python/ribasim/ribasim/schemas.py
@@ -20,6 +20,11 @@ class Config:
     def _index_name(self) -> str:
         return "fid"
 
+    @pa.dataframe_parser
+    def _name_index(cls, df):
+        df.index.name = cls._index_name()
+        return df
+
     @classmethod
     def migrate(cls, df: Any, schema_version: int) -> Any:
         f: Callable[[Any, Any], Any] = getattr(
diff --git a/python/ribasim/tests/test_io.py b/python/ribasim/tests/test_io.py
index 0320dca87..7c2dcf7b7 100644
--- a/python/ribasim/tests/test_io.py
+++ b/python/ribasim/tests/test_io.py
@@ -97,6 +97,11 @@ def test_extra_columns():
 def test_index_tables():
     p = pump.Static(flow_rate=[1.2])
     assert p.df.index.name == "fid"
+    # Index name is applied by _name_index
+    df = p.df.reset_index(drop=True)
+    assert df.index.name is None
+    p.df = df
+    assert p.df.index.name == "fid"
 
 
 def test_extra_spatial_columns():
diff --git a/python/ribasim/tests/test_model.py b/python/ribasim/tests/test_model.py
index f5e341561..9336b5275 100644
--- a/python/ribasim/tests/test_model.py
+++ b/python/ribasim/tests/test_model.py
@@ -112,6 +112,12 @@ def test_write_adds_fid_in_tables(basic, tmp_path):
     assert model_orig.edge.df.index.name == "edge_id"
     assert model_orig.edge.df.index.equals(pd.RangeIndex(1, nrow + 1))
 
+    # Index name is applied by _name_index
+    df = model_orig.edge.df.copy()
+    df.index.name = "other"
+    model_orig.edge.df = df
+    assert model_orig.edge.df.index.name == "edge_id"
+
     model_orig.write(tmp_path / "basic/ribasim.toml")
     with connect(tmp_path / "basic/database.gpkg") as connection:
         query = f"select * from {esc_id('Basin / profile')}"
diff --git a/utils/templates/schemas.py.jinja b/utils/templates/schemas.py.jinja
index 19b53c7ce..d986e4dc0 100644
--- a/utils/templates/schemas.py.jinja
+++ b/utils/templates/schemas.py.jinja
@@ -19,6 +19,11 @@ class _BaseSchema(pa.DataFrameModel):
     def _index_name(self) -> str:
         return "fid"
 
+    @pa.dataframe_parser
+    def _name_index(cls, df):
+        df.index.name = cls._index_name()
+        return df
+
     @classmethod
     def migrate(cls, df: Any, schema_version: int) -> Any:
         f: Callable[[Any, Any], Any] = getattr(