diff --git a/README.md b/README.md
index a62c7b3..0bf6785 100644
--- a/README.md
+++ b/README.md
@@ -32,6 +32,10 @@ API URL in `~/.config/asciinema/config` file as follows:
     [api]
     url = https://your.asciinema.host
 
+Alternatively, you can set `ASCIINEMA_API_URL` environment variable:
+
+    ASCIINEMA_API_URL=https://your.asciinema.host asciinema rec
+
 ## Contributing
 
 Check out our [Contributing](http://asciinema.org/contributing) page, which
diff --git a/docs/INSTALL.md b/docs/INSTALL.md
index 75d5a23..8723a83 100644
--- a/docs/INSTALL.md
+++ b/docs/INSTALL.md
@@ -143,3 +143,7 @@ API URL in `~/.config/asciinema/config` file as follows:
 
     [api]
     url = https://your.asciinema.host
+
+Alternatively, you can set `ASCIINEMA_API_URL` environment variable:
+
+    ASCIINEMA_API_URL=https://your.asciinema.host asciinema rec