diff --git a/tailscalesd/main.py b/tailscalesd/main.py
index b664cdb..ee05204 100644
--- a/tailscalesd/main.py
+++ b/tailscalesd/main.py
@@ -55,7 +55,7 @@ settings = Settings()  # type: ignore[call-arg]
 CACHE_SD = []
 
 
-async def tailscale_devices() -> List:
+async def tailscale_devices() -> List[Dict]:
     async with httpx.AsyncClient() as client:
         try:
             # https://github.com/tailscale/tailscale/blob/main/api.md#tailnet-devices-get
@@ -107,7 +107,7 @@ async def matrix_node_sd(device) -> Dict:
         return group_by_type(data)
 
 
-def matrix_workers_to_sd(tailnet, device, workers) -> List:
+def matrix_workers_to_sd(tailnet, device, workers) -> List[Dict]:
     if len(workers) == 0:
         return []
     ipv4 = ipv4_only(device["addresses"])[0]
@@ -134,8 +134,8 @@ def matrix_workers_to_sd(tailnet, device, workers) -> List:
     return target_groups
 
 
-async def matrix_sd(tailnet, devices) -> List:
-    sd = []
+async def matrix_sd(tailnet, devices) -> List[Dict]:
+    sd: List[Dict] = []
     for device in devices:
         if MATRIX_TAG not in device["tags"]:
             continue
@@ -150,12 +150,12 @@ async def matrix_sd(tailnet, devices) -> List:
             workers = {}
         targets = matrix_workers_to_sd(tailnet, device, workers)
         if targets:
-            sd.append(targets)
+            sd = sd + targets
     log.info(f"Found {len(sd)} matrix servcies")
     return sd
 
 
-def plain_devices_sd(tailnet, devices) -> List:
+def plain_devices_sd(tailnet, devices) -> List[Dict]:
     sd = []
     for device in devices:
         targets = ipv4_only(device["addresses"])