diff --git a/.gitignore b/.gitignore
index fac2e71..e33d27d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -54,6 +54,7 @@ coverage.xml
 # Sphinx documentation
 docs/*
 !docs/*.rst
+!docs/requirements.txt
 
 # PyBuilder
 target/
diff --git a/docs/requirements.txt b/docs/requirements.txt
new file mode 100644
index 0000000..8bcb836
--- /dev/null
+++ b/docs/requirements.txt
@@ -0,0 +1,6 @@
+colour
+jsonschema
+openpyxl
+pandas
+sphinx==4
+xlrd
\ No newline at end of file
diff --git a/styleframe/style_frame.py b/styleframe/style_frame.py
index e411e01..316f789 100644
--- a/styleframe/style_frame.py
+++ b/styleframe/style_frame.py
@@ -559,7 +559,7 @@ def apply_style_by_indexes(self, indexes_to_style, styler_obj, cols_to_style=Non
 
             ::
 
-                sf[sf['some_col'] = 20]
+                sf[sf['some_col'] == 20]
 
         :type indexes_to_style: list or tuple or int or Container
         :param styler_obj: `Styler` object that contains the style that will be applied to indexes in `indexes_to_style`