diff --git a/pyexcel-io.yml b/pyexcel-io.yml
index 626155e..fecf230 100644
--- a/pyexcel-io.yml
+++ b/pyexcel-io.yml
@@ -15,8 +15,10 @@ test_dependencies:
   - pyexcel-xls==0.5.9
   - SQLAlchemy
   - pyexcel-xlsxw
-extra_dependencies:
   - chardet
+extra_dependencies:
+  - extra:
+    - chardet
   - xls:
     - pyexcel-xls>=0.6.0
   - xlsx:
diff --git a/requirements.txt b/requirements.txt
index 6b8c762..8539e81 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1 @@
-chardet
 lml>=0.0.4
diff --git a/setup.py b/setup.py
index 65de74b..f226e27 100644
--- a/setup.py
+++ b/setup.py
@@ -74,7 +74,6 @@
 PYTHON_REQUIRES = ">=3.6"
 
 INSTALL_REQUIRES = [
-    "chardet",
     "lml>=0.0.4",
 ]
 SETUP_COMMANDS = {}