diff --git a/.travis.yml b/.travis.yml
index 0a8916c..78006ac 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,8 +2,6 @@ language: python
 
 matrix:
   include:
-    - python: 2.6
-      env: TOXENV=python2.6
     - python: 2.7
       env: TOXENV=python2.7
     - python: 3.3
diff --git a/requirements/requirements.txt b/requirements/requirements.txt
index 48d7ad8..cd760be 100644
--- a/requirements/requirements.txt
+++ b/requirements/requirements.txt
@@ -1,4 +1,4 @@
-DataProperty>=0.5.4
+DataProperty>=0.7.0
 jsonschema
 pathvalidate>=0.4.2
 path.py
diff --git a/requirements/test_requirements.txt b/requirements/test_requirements.txt
index 3a03f57..1ca5b54 100644
--- a/requirements/test_requirements.txt
+++ b/requirements/test_requirements.txt
@@ -1,4 +1,4 @@
-pytest
 pytest-cov
+pytest
 tox
 XlsxWriter
diff --git a/setup.py b/setup.py
index d938f4a..0e5c916 100644
--- a/setup.py
+++ b/setup.py
@@ -24,7 +24,7 @@
 
 setuptools.setup(
     name="SimpleSQLite",
-    version="0.4.1",
+    version="0.4.2",
     url="https://github.com/thombashi/SimpleSQLite",
     bugtrack_url="https://github.com/thombashi/SimpleSQLite/issues",
 
@@ -48,7 +48,6 @@
         "Operating System :: POSIX",
         "Operating System :: POSIX :: Linux",
         "Programming Language :: Python :: 2",
-        "Programming Language :: Python :: 2.6",
         "Programming Language :: Python :: 2.7",
         "Programming Language :: Python :: 3",
         "Programming Language :: Python :: 3.3",
diff --git a/simplesqlite/loader/csv/core.py b/simplesqlite/loader/csv/core.py
index 77cecfa..83ea2d2 100644
--- a/simplesqlite/loader/csv/core.py
+++ b/simplesqlite/loader/csv/core.py
@@ -53,10 +53,12 @@ def __init__(self, source):
         self.encoding = "utf-8"
 
     def _to_data_matrix(self):
+        from dataproperty.type import FloatTypeChecker
+
         return [
             [
                 six.b(data).decode(self.encoding, "ignore")
-                if not dataproperty.is_float(data) else data
+                if not FloatTypeChecker(data).is_type() else data
                 for data in row
             ]
             for row in self._csv_reader
diff --git a/simplesqlite/sqlquery.py b/simplesqlite/sqlquery.py
index c1417bf..ebc9f1b 100644
--- a/simplesqlite/sqlquery.py
+++ b/simplesqlite/sqlquery.py
@@ -174,11 +174,16 @@ def to_value_str(cls, value):
             >>> SqlQuery.to_value_str(None)
             'NULL'
         """
+        from dataproperty.type import IntegerTypeChecker
+        from dataproperty.type import FloatTypeChecker
 
         if value is None:
             return "NULL"
 
-        if dataproperty.is_integer(value) or dataproperty.is_float(value):
+        if any([
+            IntegerTypeChecker(value).is_type(),
+            FloatTypeChecker(value).is_type()
+        ]):
             return str(value)
 
         return "'%s'" % (value)
diff --git a/tox.ini b/tox.ini
index 75b4d6d..c1070a6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = python{2.6,2.7,3.3,3.4,3.5}
+envlist = python{2.7,3.3,3.4,3.5}
 
 [testenv]
 deps =