diff --git a/py-polars/polars/datatypes.py b/py-polars/polars/datatypes.py
index 2399a31c201d..b897a902fbe9 100644
--- a/py-polars/polars/datatypes.py
+++ b/py-polars/polars/datatypes.py
@@ -126,7 +126,7 @@ class DataTypeClass(type):
     def __repr__(cls) -> str:
         return cls.__name__
 
-    def string_repr(cls) -> str:
+    def _string_repr(cls) -> str:
         return dtype_str_repr(cls)
 
 
@@ -143,7 +143,7 @@ def __new__(cls, *args: Any, **kwargs: Any) -> PolarsDataType:  # type: ignore[m
     def __reduce__(self) -> Any:
         return (_custom_reconstruct, (type(self), object, None), self.__dict__)
 
-    def string_repr(self) -> str:
+    def _string_repr(self) -> str:
         return dtype_str_repr(self)
 
 
diff --git a/py-polars/polars/internals/dataframe/frame.py b/py-polars/polars/internals/dataframe/frame.py
index 6e3ce1863aad..103143d01cb0 100644
--- a/py-polars/polars/internals/dataframe/frame.py
+++ b/py-polars/polars/internals/dataframe/frame.py
@@ -2786,9 +2786,9 @@ def glimpse(self: DF) -> str:
 
         def _parse_column(col_name: str, dtype: PolarsDataType) -> tuple[str, str, str]:
             dtype_str = (
-                f"<{DataTypeClass.string_repr(dtype)}>"
+                f"<{DataTypeClass._string_repr(dtype)}>"
                 if isinstance(dtype, DataTypeClass)
-                else f"<{dtype.string_repr()}>"
+                else f"<{dtype._string_repr()}>"
             )
             val = self[:max_num_values][col_name].to_list()
             val_str = ", ".join(map(str, val))