diff --git a/docs/source/installation.md b/docs/source/installation.md
index 88107c94871..d77253f0f92 100644
--- a/docs/source/installation.md
+++ b/docs/source/installation.md
@@ -228,7 +228,7 @@ Alternatively, to install all optional dependencies:
 ```bash
 git clone https://github.com/Project-MONAI/MONAI.git
 cd MONAI/
-pip install -e '.[all]'
+pip install -e ".[all]"
 ```
 
 To install all optional dependencies with `pip` based on MONAI development environment settings: