diff --git a/src/snekbot/rpc.py b/src/snekbot/rpc.py
index 73343ad..e29528b 100644
--- a/src/snekbot/rpc.py
+++ b/src/snekbot/rpc.py
@@ -52,7 +52,7 @@ class RPC:
         self.ws = ws
         self.current_call_id = None
         self.queue = asyncio.Queue()
-        self.semaphore = asyncio.Semaphore(200)
+        self.semaphore = asyncio.Semaphore(1)
 
     def __getattr__(self, name):
         async def method(*args, **kwargs):
@@ -78,7 +78,7 @@ class RPC:
 
             if no_response:
                 return True
-            with self.semaphore:
+            async with self.semaphore:
                 return await poller()
 
         return method