diff --git a/message_ix_models/report/util.py b/message_ix_models/report/util.py
index 3015c64ce2..c702e317e2 100644
--- a/message_ix_models/report/util.py
+++ b/message_ix_models/report/util.py
@@ -61,7 +61,7 @@
 
 
 def collapse(df, var_name, var=[], region=[], replace_common=True):
-    """Callback for the `collapse argument to :meth:`~.Reporter.convert_pyam.
+    """Callback for the `collapse` argument to :meth:`~.Reporter.convert_pyam`.
 
     The dimensions listed in the `var` and `region` arguments are automatically
     dropped from the returned :class:`pyam.IamDataFrame`.