diff --git a/src/aioappsrv/app.py b/src/aioappsrv/app.py
index 48d1e59..ac1092c 100644
--- a/src/aioappsrv/app.py
+++ b/src/aioappsrv/app.py
@@ -86,8 +86,11 @@ class AppService:
 			},
 			params={"user_id": mxid} if mxid else {},
 		) as res:
-			doc = await res.json()
-		self.logger.debug("joined room %s with %s : %s", room, mxid, doc)
+			if res.ok:
+				self.logger.debug("joined room %s with %s : %s", room, mxid, await res.json())
+			else:
+				self.logger.error("failed sending message: %s", await res.text())
+				raise ValueError()
 
 	async def leave_room(self):
 		raise NotImplementedError
@@ -103,13 +106,14 @@ class AppService:
 			params={"user_id": mxid} if mxid else {},
 			json=mx_message(text),
 		) as res:
-			doc = await res.json()
-		if "event_id" in doc:
-			self.logger.debug("sent message %s to %s as %s : %s", text, room, mxid, doc)
-			return doc["event_id"]
-		else:
-			self.logger.error("failed sending message: %s", doc)
-			raise ValueError(doc)
+			if res.ok:
+				doc = await res.json()
+				self.logger.debug("sent message %s to %s as %s : %s", text, room, mxid, doc)
+				return doc["event_id"]
+			else:
+				text = await res.text()
+				self.logger.error("failed sending message: %s", text)
+				raise ValueError()
 
 	async def redact_message(self):
 		raise NotImplementedError