diff --git a/README.md b/README.md
index 7fd173513..005ee0f8d 100644
--- a/README.md
+++ b/README.md
@@ -95,3 +95,8 @@ Last, run the emulator with following command:
 ```
 cd emu && reader.lua -d ./
 ```
+
+You can also specify size of emulator's screen via environment variables.
+For more information, please refer to [koreader-base's README][base-readme].
+
+[base-readme]:https://github.com/koreader/koreader-base