diff --git a/jsignature/fields.py b/jsignature/fields.py
index 0fece1d..ff76904 100644
--- a/jsignature/fields.py
+++ b/jsignature/fields.py
@@ -12,13 +12,6 @@
     JSIGNATURE_EMPTY_VALUES,
 )
 
-try:
-    from django.utils import six
-
-    string_types = six.string_types
-except ImportError:
-    string_types = str
-
 
 class JSignatureField(models.Field):
     """
@@ -46,7 +39,7 @@ def to_python(self, value):
     def get_prep_value(self, value):
         if value in JSIGNATURE_EMPTY_VALUES:
             return None
-        elif isinstance(value, string_types):
+        elif isinstance(value, str):
             return value
         elif isinstance(value, list):
             return json.dumps(value)
diff --git a/jsignature/widgets.py b/jsignature/widgets.py
index dc1d65f..ed26dc2 100644
--- a/jsignature/widgets.py
+++ b/jsignature/widgets.py
@@ -17,13 +17,6 @@
 JSIGNATURE_EMPTY_VALUES = validators.EMPTY_VALUES + ('[]', )
 
 
-try:
-    from django.utils import six
-    string_types = six.string_types
-except ImportError:
-    string_types = str
-
-
 class JSignatureWidget(forms.HiddenInput):
     """
     A widget handling a signature capture field with with jSignature
@@ -73,7 +66,7 @@ def prep_value(self, value):
         """ Prepare value before effectively render widget """
         if value in JSIGNATURE_EMPTY_VALUES:
             return "[]"
-        elif isinstance(value, string_types):
+        elif isinstance(value, str):
             return value
         elif isinstance(value, list):
             return json.dumps(value)