diff --git a/bibtexparser/middlewares/month.py b/bibtexparser/middlewares/month.py
index 0dbd6210..31c9ec20 100644
--- a/bibtexparser/middlewares/month.py
+++ b/bibtexparser/middlewares/month.py
@@ -12,7 +12,7 @@ class _MonthInterpolator(BlockMiddleware, abc.ABC):
     """Abstract class to handle month-conversions."""
 
     # docstr-coverage: inherited
-    def __init__(self, allow_inplace_modification: bool):
+    def __init__(self, allow_inplace_modification: bool = True):
         super().__init__(
             allow_inplace_modification=allow_inplace_modification,
             allow_parallel_execution=True,
diff --git a/docs/source/customize.rst b/docs/source/customize.rst
index 3ff81cee..ca193f19 100644
--- a/docs/source/customize.rst
+++ b/docs/source/customize.rst
@@ -16,7 +16,7 @@ The core functionality of bibtexparser is deliberately kept simple:
 * Upon writing, the splitting is reversed and the blocks are joined together again, with few formatting options.
 
 Advanced transformations of blocks, such as sorting, encoding, cross-referencing, etc. are not part of the core functionality,
-but can be optionally added to the parse stack by using the corresponging middleware layers:
+but can be optionally added to the parse stack by using the corresponding middleware layers:
 Middleware layers helper classes providing the functionality take a library object and return a new, transformed version of said library.
 
 Middleware Layers
@@ -28,9 +28,9 @@ Middleware Layers
 
     # We want to add three new middleware layers to our parse stack:
     layers = [
-        m.MonthIntMiddleware(True), # Months should be represented as int (0-12)
-        m.SeparateCoAuthors(True), # Co-authors should be separated as list of strings
-        m.SplitNameParts(True) # Individual Names should be split into first, von, last, jr parts
+        m.MonthIntMiddleware(), # Months should be represented as int (0-12)
+        m.SeparateCoAuthors(), # Co-authors should be separated as list of strings
+        m.SplitNameParts() # Individual Names should be split into first, von, last, jr parts
     ]
     library = bibtexparser.parse_file('bibtex.bib', append_middleware=layers)
 
@@ -147,4 +147,4 @@ Specifically, a user may pass a :class:`bibtexparser.BibtexFormatter` object to
     bib_str = bibtexparser.write_string(library, bibtex_format=bibtex_format)
 
 A few more options are provided and we refer to the docstrings of :class:`bibtexparser.BibtexFormat` for details.
-Note: Sorting of blocks and fields is done with the corresponding middleware, as described above.
\ No newline at end of file
+Note: Sorting of blocks and fields is done with the corresponding middleware, as described above.
diff --git a/examples/middelware.ipynb b/examples/middelware.ipynb
index 750e3268..a466c54b 100644
--- a/examples/middelware.ipynb
+++ b/examples/middelware.ipynb
@@ -101,9 +101,9 @@
     "\n",
     "# We want to add three new middleware layers to our parse stack:\n",
     "layers = [\n",
-    "    m.MonthIntMiddleware(True), # Months should be represented as int (0-12)\n",
-    "    m.SeparateCoAuthors(True), # Co-authors should be separated\n",
-    "    m.SplitNameParts(True) # Names should be split into first, von, last, jr parts\n",
+    "    m.MonthIntMiddleware(), # Months should be represented as int (0-12)\n",
+    "    m.SeparateCoAuthors(), # Co-authors should be separated\n",
+    "    m.SplitNameParts() # Names should be split into first, von, last, jr parts\n",
     "]\n",
     "library_append_pstack = bibtexparser.parse_file('bibtex.bib', append_middleware=layers)\n",
     "\n",