diff --git a/docs/Makefile b/docs/Makefile
index 94224689..9be55735 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -48,7 +48,7 @@ help:
 	@echo "  doctest	to run all doctests embedded in the documentation (if enabled)"
 
 clean:
-	rm $(AUTOSUMMARYDIR)/*
+	rm -f $(AUTOSUMMARYDIR)/*
 	rm -rf $(BUILDDIR)/*
 
 html:
diff --git a/docs/source/conf/80-scico_numpy.py b/docs/source/conf/80-scico_numpy.py
index 8d495250..eaad4312 100644
--- a/docs/source/conf/80-scico_numpy.py
+++ b/docs/source/conf/80-scico_numpy.py
@@ -27,7 +27,7 @@
         # Improve formatting of jax.numpy warning
         f.__doc__ = re.sub(
             r"^\*\*\* This function is not yet implemented by jax.numpy, and will "
-            "raise NotImplementedError \*\*\*",
+            r"raise NotImplementedError \*\*\*",
             "**WARNING**: This function is not yet implemented by jax.numpy, "
             " and will raise :exc:`NotImplementedError`.",
             f.__doc__,
@@ -52,14 +52,14 @@
     flags=re.M,
 )
 scico.numpy.testing.break_cycles.__doc__ = re.sub(
-    " __del__\) inside", "__del__\) inside", scico.numpy.testing.break_cycles.__doc__, flags=re.M
+    r" __del__\) inside", r"__del__\) inside", scico.numpy.testing.break_cycles.__doc__, flags=re.M
 )
 scico.numpy.testing.assert_raises_regex.__doc__ = re.sub(
-    "\*args,\n.*\*\*kwargs",
+    r"\*args,\n.*\*\*kwargs",
     "*args, **kwargs",
     scico.numpy.testing.assert_raises_regex.__doc__,
     flags=re.M,
 )
 scico.numpy.BlockArray.global_shards.__doc__ = re.sub(
-    "`Shard`s", "`Shard`\ s", scico.numpy.BlockArray.global_shards.__doc__, flags=re.M
+    r"`Shard`s", r"`Shard`\ s", scico.numpy.BlockArray.global_shards.__doc__, flags=re.M
 )
diff --git a/docs/source/conf/81-scico_scipy.py b/docs/source/conf/81-scico_scipy.py
index ad4893c7..82ef91df 100644
--- a/docs/source/conf/81-scico_scipy.py
+++ b/docs/source/conf/81-scico_scipy.py
@@ -28,8 +28,8 @@
         # Remove entire numpydoc references section
         f.__doc__ = re.sub(r"References\n----------\n.*\n", "", f.__doc__, flags=re.DOTALL)
         # Remove problematic citation
-        f.__doc__ = re.sub("See \[dlmf\]_ for details.", "", f.__doc__, re.M)
-        f.__doc__ = re.sub("\[dlmf\]_", "NIST DLMF", f.__doc__, re.M)
+        f.__doc__ = re.sub(r"See \[dlmf\]_ for details.", "", f.__doc__, re.M)
+        f.__doc__ = re.sub(r"\[dlmf\]_", "NIST DLMF", f.__doc__, re.M)
 
 # Fix indentation problems
 scico.scipy.special.sph_harm.__doc__ = re.sub(
diff --git a/docs/source/conf/85-dtype_typehints.py b/docs/source/conf/85-dtype_typehints.py
index bcaa4339..94b99d59 100644
--- a/docs/source/conf/85-dtype_typehints.py
+++ b/docs/source/conf/85-dtype_typehints.py
@@ -31,10 +31,10 @@ def typehints_formatter_function(annotation, config):
         DType: ":obj:`~scico.typing.DType`",
         # Compound types involving DType must be added here to avoid their DType
         # component being expanded in the docs.
-        Optional[DType]: ":obj:`~typing.Optional`\ [\ :obj:`~scico.typing.DType`\ ]",
+        Optional[DType]: r":obj:`~typing.Optional`\ [\ :obj:`~scico.typing.DType`\ ]",
         Union[DType, Sequence[DType]]: (
-            ":obj:`~typing.Union`\ [\ :obj:`~scico.typing.DType`\ , "
-            ":obj:`~typing.Sequence`\ [\ :obj:`~scico.typing.DType`\ ]]"
+            r":obj:`~typing.Union`\ [\ :obj:`~scico.typing.DType`\ , "
+            r":obj:`~typing.Sequence`\ [\ :obj:`~scico.typing.DType`\ ]]"
         ),
         AxisIndex: ":obj:`~scico.typing.AxisIndex`",
         ArrayIndex: ":obj:`~scico.typing.ArrayIndex`",