diff --git a/python/cudf/cudf/core/dataframe.py b/python/cudf/cudf/core/dataframe.py
index 605c1fbc6c6..d04a0bcf62d 100644
--- a/python/cudf/cudf/core/dataframe.py
+++ b/python/cudf/cudf/core/dataframe.py
@@ -7517,10 +7517,11 @@ def merge(left, right, *args, **kwargs):
 
 # a bit of fanciness to inject docstring with left parameter
 merge_doc = DataFrame.merge.__doc__
-idx = merge_doc.find("right")
-merge.__doc__ = "".join(
-    [merge_doc[:idx], "\n\tleft : DataFrame\n\t", merge_doc[idx:]]
-)
+if merge_doc is not None:
+    idx = merge_doc.find("right")
+    merge.__doc__ = "".join(
+        [merge_doc[:idx], "\n\tleft : DataFrame\n\t", merge_doc[idx:]]
+    )
 
 
 def _align_indices(lhs, rhs):
diff --git a/python/cudf/cudf/utils/docutils.py b/python/cudf/cudf/utils/docutils.py
index a4c35d0459a..57ad612846d 100644
--- a/python/cudf/cudf/utils/docutils.py
+++ b/python/cudf/cudf/utils/docutils.py
@@ -27,6 +27,8 @@ def docfmt(**kwargs):
 
     def outer(fn):
         buf = []
+        if fn.__doc__ is None:
+            return fn
         formatsiter = string.Formatter().parse(fn.__doc__)
         for literal, field, fmtspec, conv in formatsiter:
             assert conv is None
@@ -44,7 +46,6 @@ def outer(fn):
                     buf.extend([indent + ln for ln in valuelines[1:]])
                 else:
                     buf.append(kwargs[field])
-
         fn.__doc__ = "".join(buf)
         return fn