diff --git a/aiopools/__init__.py b/aiopools/__init__.py
index 09480cd..b9b59c9 100644
--- a/aiopools/__init__.py
+++ b/aiopools/__init__.py
@@ -4,6 +4,9 @@
 class AsyncPool:
     
     def __init__(self, maxio: int = 20):
+        '''
+            maxio: The maximum number of coroutines allowed by the system.
+        '''
         self.semaphore = asyncio.Semaphore(maxio)
         self.tasks = []