diff --git a/setup.py b/setup.py
index f226e27..f444c91 100644
--- a/setup.py
+++ b/setup.py
@@ -80,6 +80,7 @@
 
 PACKAGES = find_packages(exclude=["ez_setup", "examples", "tests", "tests.*"])
 EXTRAS_REQUIRE = {
+    "extra": ['chardet'],
     "xls": ['pyexcel-xls>=0.6.0'],
     "xlsx": ['pyexcel-xlsx>=0.6.0'],
     "ods": ['pyexcel-ods3>=0.6.0'],
diff --git a/tests/requirements.txt b/tests/requirements.txt
index be90c0a..29d4c98 100644
--- a/tests/requirements.txt
+++ b/tests/requirements.txt
@@ -13,3 +13,4 @@ pyexcel
 pyexcel-xls==0.5.9
 SQLAlchemy
 pyexcel-xlsxw
+chardet