diff --git a/CHANGELOG.md b/CHANGELOG.md
index a27edbe0..78d8a44f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,10 @@
 Changes
 =======
 
+Version 2.6.0
+
+1. Drop utils.is_str function
+
 Version 2.5.0
 -------------
 
diff --git a/src/pygccxml/utils/__init__.py b/src/pygccxml/utils/__init__.py
index 1730aee0..84df5cf6 100644
--- a/src/pygccxml/utils/__init__.py
+++ b/src/pygccxml/utils/__init__.py
@@ -8,7 +8,6 @@
 
 """
 
-from .utils import is_str
 from .utils import get_architecture
 from .utils import loggers
 from .utils import create_temp_file_name
diff --git a/src/pygccxml/utils/utils.py b/src/pygccxml/utils/utils.py
index 7a9deb5a..0d1022dc 100644
--- a/src/pygccxml/utils/utils.py
+++ b/src/pygccxml/utils/utils.py
@@ -7,36 +7,12 @@
 
 import os
 import sys
-import platform
 import logging
 import tempfile
 import shutil
-import subprocess
 import warnings
 
 
-def is_str(string):
-    """
-    Python 2 and 3 compatible string checker.
-
-    Args:
-        string (str | basestring): the string to check
-
-    Returns:
-        bool: True or False
-
-    """
-    warnings.warn(
-        "The is_str function is deprecated. \
-        Use isinstance(string, str) instead.",
-        DeprecationWarning)
-
-    if sys.version_info[:2] >= (3, 0):
-        return isinstance(string, str)
-
-    return isinstance(string, basestring)
-
-
 def find_xml_generator(name="castxml", search_path=None):
     """
     Try to find a c++ parser (xml generator)