diff --git a/README.md b/README.md
index ae25d0e..e211c43 100644
--- a/README.md
+++ b/README.md
@@ -45,7 +45,7 @@ How to use
 
 * (Optionally) install extra dependencies for extracting images.
 
-  `pip install 'pdfminer.six[image]`
+  `pip install 'pdfminer.six[image]'`
 
 * Use command-line interface to extract text from pdf:
 
@@ -59,4 +59,4 @@ Be sure to read the [contribution guidelines](https://github.com/pdfminer/pdfmin
 Acknowledgement
 ---------------
 
-This repository includes code from `pyHanko` ; the original license has been included [here](/docs/licenses/LICENSE.pyHanko).
\ No newline at end of file
+This repository includes code from `pyHanko` ; the original license has been included [here](/docs/licenses/LICENSE.pyHanko).