diff --git a/src/sciline/param_table.py b/src/sciline/param_table.py
index 585f7e8e..50ff35b9 100644
--- a/src/sciline/param_table.py
+++ b/src/sciline/param_table.py
@@ -71,12 +71,15 @@ def __len__(self) -> int:
         return self._columns.__len__()
 
     def __repr__(self) -> str:
-        return f"ParamTable(row_dim={self.row_dim}, columns={self._columns})"
+        return f"ParamTable(row_dim={self.row_dim.__name__}, columns={self._columns})"
 
     def _repr_html_(self) -> str:
         return (
             f"<table><tr><th>{self.row_dim.__name__}</th>"
-            + "".join(f"<th>{k.__name__}</th>" for k in self._columns.keys())
+            + "".join(
+                f"<th>{getattr(k, '__name__', str(k).split('.')[-1])}</th>"
+                for k in self._columns.keys()
+            )
             + "</tr>"
             + "".join(
                 f"<tr><td>{idx}</td>" + "".join(f"<td>{v}</td>" for v in row) + "</tr>"
diff --git a/src/sciline/series.py b/src/sciline/series.py
index fb82ca0b..2b5b5607 100644
--- a/src/sciline/series.py
+++ b/src/sciline/series.py
@@ -43,7 +43,7 @@ def __getitem__(self, key: Key) -> Value:
         return self._map[key]
 
     def __repr__(self) -> str:
-        return f"Series(row_dim={self.row_dim}, {self._map})"
+        return f"Series(row_dim={self.row_dim.__name__}, {self._map})"
 
     def _repr_html_(self) -> str:
         return (