diff --git a/.gitignore b/.gitignore
index c47edb777..4a9c9ab80 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,6 +7,10 @@ build
 *.egg-info/
 dist/*
 
+#
+.mutmut-cache
+mutmut-results.*
+
 # Code coverage artifacts
 .coverage*
 coverage.xml
diff --git a/Makefile b/Makefile
index 8516f1e25..a6bbb5ddc 100644
--- a/Makefile
+++ b/Makefile
@@ -15,3 +15,10 @@ clean:
 
 test:
 	pytest Tests --cov --cov-report term-missing -vv --cov-report html
+
+mutation-test:
+	mutmut run
+
+mutmut-results:
+	mutmut junitxml --suspicious-policy=ignore --untested-policy=ignore > mutmut-results.xml
+	junit2html mutmut-results.xml mutmut-results.html
diff --git a/PyPDF2/filters.py b/PyPDF2/filters.py
index 8b72f0932..6a409a62e 100644
--- a/PyPDF2/filters.py
+++ b/PyPDF2/filters.py
@@ -157,11 +157,11 @@ def decode(data, decodeParms):
                 # unsupported predictor
                 raise PdfReadError("Unsupported flatedecode predictor %r" % predictor)
         return data
-    decode = staticmethod(decode)
+    decode = staticmethod(decode)  # type: ignore
 
     def encode(data):
         return compress(data)
-    encode = staticmethod(encode)
+    encode = staticmethod(encode)  # type: ignore
 
 
 class ASCIIHexDecode(object):
@@ -183,7 +183,7 @@ def decode(data, decodeParms=None):
             x += 1
         assert char == ""
         return retval
-    decode = staticmethod(decode)
+    decode = staticmethod(decode)  # type: ignore
 
 
 class LZWDecode(object):
@@ -339,17 +339,17 @@ def decode(data, decodeParms=None):
                         out += struct.pack(b'>L',b)[:n-1]
                     break
             return bytes(out)
-    decode = staticmethod(decode)
+    decode = staticmethod(decode)  # type: ignore
 
 class DCTDecode(object):
     def decode(data, decodeParms=None):
         return data
-    decode = staticmethod(decode)
+    decode = staticmethod(decode)  # type: ignore
 
 class JPXDecode(object):
     def decode(data, decodeParms=None):
         return data
-    decode = staticmethod(decode)
+    decode = staticmethod(decode)  # type: ignore
 
 class CCITTFaxDecode(object):
     def decode(data, decodeParms=None, height=0):
@@ -384,7 +384,7 @@ def decode(data, decodeParms=None, height=0):
 
         return tiffHeader + data
 
-    decode = staticmethod(decode)
+    decode = staticmethod(decode)  # type: ignore
 
 def decodeStreamData(stream):
     from .generic import NameObject
diff --git a/PyPDF2/generic.py b/PyPDF2/generic.py
index 2ae9a7471..c0691694d 100644
--- a/PyPDF2/generic.py
+++ b/PyPDF2/generic.py
@@ -1,5 +1,3 @@
-# vim: sw=4:expandtab:foldmethod=marker
-#
 # Copyright (c) 2006, Mathieu Fenniak
 # All rights reserved.
 #
@@ -114,7 +112,7 @@ def readFromStream(stream):
         if nulltxt != b_("null"):
             raise utils.PdfReadError("Could not read Null object")
         return NullObject()
-    readFromStream = staticmethod(readFromStream)
+    readFromStream = staticmethod(readFromStream)  # type: ignore
 
 
 class BooleanObject(PdfObject):
@@ -136,7 +134,7 @@ def readFromStream(stream):
             return BooleanObject(False)
         else:
             raise utils.PdfReadError('Could not read Boolean object')
-    readFromStream = staticmethod(readFromStream)
+    readFromStream = staticmethod(readFromStream)  # type: ignore
 
 
 class ArrayObject(list, PdfObject):
@@ -166,7 +164,7 @@ def readFromStream(stream, pdf):
             # read and append obj
             arr.append(readObject(stream, pdf))
         return arr
-    readFromStream = staticmethod(readFromStream)
+    readFromStream = staticmethod(readFromStream)  # type: ignore
 
 
 class IndirectObject(PdfObject):
@@ -219,7 +217,7 @@ def readFromStream(stream, pdf):
         if r != b_("R"):
             raise utils.PdfReadError("Error reading indirect object reference at byte %s" % utils.hexStr(stream.tell()))
         return IndirectObject(int(idnum), int(generation), pdf)
-    readFromStream = staticmethod(readFromStream)
+    readFromStream = staticmethod(readFromStream)  # type: ignore
 
 
 class FloatObject(decimal.Decimal, PdfObject):
@@ -270,7 +268,7 @@ def readFromStream(stream):
             return FloatObject(num)
         else:
             return NumberObject(num)
-    readFromStream = staticmethod(readFromStream)
+    readFromStream = staticmethod(readFromStream)  # type: ignore
 
 
 def createStringObject(string):
@@ -391,7 +389,7 @@ def readStringFromStream(stream):
     return createStringObject(txt)
 
 
-class ByteStringObject(utils.bytes_type, PdfObject):
+class ByteStringObject(utils.bytes_type, PdfObject):  # type: ignore
     """
     Represents a string object where the text encoding could not be determined.
     This occurs quite often, as the PDF spec doesn't provide an alternate way to
@@ -413,7 +411,7 @@ def writeToStream(self, stream, encryption_key):
         stream.write(b_(">"))
 
 
-class TextStringObject(utils.string_type, PdfObject):
+class TextStringObject(utils.string_type, PdfObject):  # type: ignore
     """
     Represents a string object that has been decoded into a real unicode string.
     If read from a PDF document, this string appeared to match the
@@ -497,7 +495,7 @@ def readFromStream(stream, pdf):
             else:
                 raise utils.PdfReadError("Illegal character in Name Object")
 
-    readFromStream = staticmethod(readFromStream)
+    readFromStream = staticmethod(readFromStream)  # type: ignore
 
 
 class DictionaryObject(dict, PdfObject):
@@ -642,7 +640,7 @@ def readFromStream(stream, pdf):
             retval = DictionaryObject()
             retval.update(data)
             return retval
-    readFromStream = staticmethod(readFromStream)
+    readFromStream = staticmethod(readFromStream)  # type: ignore
 
 
 class TreeObject(DictionaryObject):
@@ -802,7 +800,7 @@ def initializeFromDictionary(data):
         del data["/Length"]
         retval.update(data)
         return retval
-    initializeFromDictionary = staticmethod(initializeFromDictionary)
+    initializeFromDictionary = staticmethod(initializeFromDictionary)  # type: ignore
 
     def flateEncode(self):
         if "/Filter" in self:
diff --git a/PyPDF2/pdf.py b/PyPDF2/pdf.py
index 6d1824384..547284f80 100644
--- a/PyPDF2/pdf.py
+++ b/PyPDF2/pdf.py
@@ -2224,7 +2224,7 @@ def createBlankPage(pdf=None, width=None, height=None):
             RectangleObject([0, 0, width, height]))
 
         return page
-    createBlankPage = staticmethod(createBlankPage)
+    createBlankPage = staticmethod(createBlankPage)  # type: ignore
 
     def rotateClockwise(self, angle):
         """
@@ -2266,7 +2266,7 @@ def _mergeResources(res1, res2, resource):
             elif key not in newRes:
                 newRes[key] = page2Res.raw_get(key)
         return newRes, renameRes
-    _mergeResources = staticmethod(_mergeResources)
+    _mergeResources = staticmethod(_mergeResources)  # type: ignore
 
     def _contentStreamRename(stream, rename, pdf):
         if not rename:
@@ -2286,7 +2286,7 @@ def _contentStreamRename(stream, rename, pdf):
             else:
                 raise KeyError ("type of operands is %s" % type (operands))
         return stream
-    _contentStreamRename = staticmethod(_contentStreamRename)
+    _contentStreamRename = staticmethod(_contentStreamRename)  # type: ignore
 
     def _pushPopGS(contents, pdf):
         # adds a graphics state "push" and "pop" to the beginning and end
@@ -2296,7 +2296,7 @@ def _pushPopGS(contents, pdf):
         stream.operations.insert(0, [[], "q"])
         stream.operations.append([[], "Q"])
         return stream
-    _pushPopGS = staticmethod(_pushPopGS)
+    _pushPopGS = staticmethod(_pushPopGS)  # type: ignore
 
     def _addTransformationMatrix(contents, pdf, ctm):
         # adds transformation matrix at the beginning of the given
@@ -2307,7 +2307,7 @@ def _addTransformationMatrix(contents, pdf, ctm):
             FloatObject(c), FloatObject(d), FloatObject(e),
             FloatObject(f)], " cm"])
         return contents
-    _addTransformationMatrix = staticmethod(_addTransformationMatrix)
+    _addTransformationMatrix = staticmethod(_addTransformationMatrix)  # type: ignore
 
     def getContents(self):
         """
diff --git a/PyPDF2/utils.py b/PyPDF2/utils.py
index 87b3a8b24..639471d4a 100644
--- a/PyPDF2/utils.py
+++ b/PyPDF2/utils.py
@@ -35,9 +35,10 @@
 import sys
 
 try:
-    import __builtin__ as builtins
-except ImportError:  # Py3
     import builtins
+    from typing import Dict
+except ImportError:  # Py2.7
+    import __builtin__ as builtins  # type: ignore
 
 ERR_STREAM_TRUNCATED_PREMATURELY = "Stream has ended unexpectedly"
 xrange_fn = getattr(builtins, "xrange", range)
@@ -45,7 +46,7 @@
 
 bytes_type = type(bytes()) # Works the same in Python 2.X and 3.X
 string_type = getattr(builtins, "unicode", str)
-int_types = (int, long) if sys.version_info[0] < 3 else (int,)  # noqa
+int_types = (int, long) if sys.version_info[0] < 3 else (int,)  # type: ignore  # noqa
 
 
 # Make basic type tests more consistent
@@ -227,7 +228,7 @@ class PdfStreamError(PdfReadError):
     def b_(s):
         return s
 else:
-    B_CACHE = {}
+    B_CACHE = {}  # type: Dict[str, bytes]
 
     def b_(s):
         bc = B_CACHE
diff --git a/Tests/test_pagerange.py b/Tests/test_pagerange.py
index 05bd5fee0..b90feef00 100644
--- a/Tests/test_pagerange.py
+++ b/Tests/test_pagerange.py
@@ -58,3 +58,10 @@ def test_parse_filename_page_ranges(params, expected):
 def test_parse_filename_page_ranges_err():
     with pytest.raises(ValueError):
         parse_filename_page_ranges(["1:5", "foo.pdf"])
+
+
+def test_page_range_help():
+    from PyPDF2.pagerange import PAGE_RANGE_HELP
+    assert len(PAGE_RANGE_HELP) > 20
+    assert "0:3" in PAGE_RANGE_HELP
+    assert PAGE_RANGE_HELP.endswith("\n")
diff --git a/mutmut-test.sh b/mutmut-test.sh
new file mode 100644
index 000000000..94cbc86a8
--- /dev/null
+++ b/mutmut-test.sh
@@ -0,0 +1,2 @@
+#!/bin/bash -e
+pytest -x
\ No newline at end of file