diff --git a/ircrobots/ircv3.py b/ircrobots/ircv3.py
index 833b46b..a31efe6 100644
--- a/ircrobots/ircv3.py
+++ b/ircrobots/ircv3.py
@@ -75,6 +75,14 @@ def _cap_dict(s: str) -> Dict[str, str]:
         d[key] = value
     return d
 
+async def sts_transmute(params: ConnectionParams):
+    if not params.sts is None and not params.tls:
+        now   = time()
+        since = (now-params.sts.created)
+        if since <= params.sts.duration:
+            params.port = params.sts.port
+            params.tls  = True
+
 class CAPContext(ServerContext):
     async def on_ls(self, tokens: Dict[str, str]):
         caps = list(self.server.desired_caps)+CAPS
@@ -126,12 +134,3 @@ class CAPContext(ServerContext):
 
         await self.on_ls(self.server.available_caps)
         await self.server.send(build("CAP", ["END"]))
-
-class STSContext(ServerContext):
-    async def transmute(self, params: ConnectionParams):
-        if not params.sts is None and not params.tls:
-            now   = time()
-            since = (now-params.sts.created)
-            if since <= params.sts.duration:
-                params.port = params.sts.port
-                params.tls  = True
diff --git a/ircrobots/server.py b/ircrobots/server.py
index 7e2fb86..09cb776 100644
--- a/ircrobots/server.py
+++ b/ircrobots/server.py
@@ -8,8 +8,8 @@ from ircstates.numerics import *
 from ircstates.server   import ServerDisconnectedException
 from irctokens          import build, Line, tokenise
 
-from .ircv3     import (CAPContext, STSContext, CAP_ECHO, CAP_SASL, CAP_LABEL,
-    LABEL_TAG)
+from .ircv3     import (CAPContext, sts_transmute, CAP_ECHO, CAP_SASL,
+    CAP_LABEL, LABEL_TAG)
 from .sasl      import SASLContext, SASLResult
 from .join_info import WHOContext
 from .matching  import ResponseOr, Responses, Response, ParamAny, ParamFolded
@@ -84,7 +84,7 @@ class Server(IServer):
     async def connect(self,
             transport: ITCPTransport,
             params: ConnectionParams):
-        await STSContext(self).transmute(params)
+        await sts_transmute(params)
 
         reader, writer = await transport.connect(
             params.host,