diff --git a/doc/release_notes.rst b/doc/release_notes.rst
index 3a7871043..e343953f5 100644
--- a/doc/release_notes.rst
+++ b/doc/release_notes.rst
@@ -20,6 +20,11 @@ Upcoming Release
 
 * Files extracted from sector-coupled data bundle have been moved from ``data/`` to ``data/sector-bundle``.
 
+
+**Bugs and Compatibility**
+
+* A bug preventing custom powerplants specified in ``data/custom_powerplants.csv`` was fixed. (https://github.com/PyPSA/pypsa-eur/pull/732)
+
 PyPSA-Eur 0.8.1 (27th July 2023)
 ================================
 
diff --git a/scripts/build_powerplants.py b/scripts/build_powerplants.py
index cbe945050..24eed6de2 100755
--- a/scripts/build_powerplants.py
+++ b/scripts/build_powerplants.py
@@ -89,7 +89,7 @@
 def add_custom_powerplants(ppl, custom_powerplants, custom_ppl_query=False):
     if not custom_ppl_query:
         return ppl
-    add_ppls = pd.read_csv(custom_powerplants, index_col=0, dtype={"bus": "str"})
+    add_ppls = pd.read_csv(custom_powerplants, dtype={"bus": "str"})
     if isinstance(custom_ppl_query, str):
         add_ppls.query(custom_ppl_query, inplace=True)
     return pd.concat(