diff --git a/modules/client/login.cc b/modules/client/login.cc
index f4fc3e427..88e1b3ca7 100644
--- a/modules/client/login.cc
+++ b/modules/client/login.cc
@@ -62,15 +62,15 @@ post_login_password(client &client,
 	};
 
 	if(!user.is_password(supplied_password))
-		throw m::error
+		throw m::FORBIDDEN
 		{
-			http::FORBIDDEN, "M_FORBIDDEN", "Access denied."
+			"Access denied."
 		};
 
 	if(!user.is_active())
-		throw m::error
+		throw m::FORBIDDEN
 		{
-			http::FORBIDDEN, "M_FORBIDDEN", "Access denied."
+			"Access denied."
 		};
 
 	// Generate the access token
diff --git a/modules/client/register.cc b/modules/client/register.cc
index 50872ec1c..5da7053f8 100644
--- a/modules/client/register.cc
+++ b/modules/client/register.cc
@@ -52,9 +52,9 @@ try
 
 	// We only support this for now, for some reason. TODO: XXX
 	if(type && type != "m.login.dummy")
-		throw m::error
+		throw m::UNSUPPORTED
 		{
-			"M_UNSUPPORTED", "Registration '%s' not supported.", type
+			"Registration '%s' not supported.", type
 		};
 
 	// 3.3.1 The local part of the desired Matrix ID. If omitted, the homeserver MUST
@@ -126,8 +126,7 @@ catch(const m::INVALID_MXID &e)
 {
 	throw m::error
 	{
-		http::BAD_REQUEST,
-		"M_INVALID_USERNAME",
+		http::BAD_REQUEST, "M_INVALID_USERNAME",
 		"Not a valid username. Please try again."
 	};
 };
@@ -167,10 +166,8 @@ handle_post(client &client,
 	if(kind.empty() || kind == "user")
 		return handle_post_kind_user(client, request);
 
-	throw m::error
+	throw m::UNSUPPORTED
 	{
-		http::BAD_REQUEST,
-		"M_UNKNOWN",
 		"Unknown 'kind' of registration specified in query."
 	};
 }
diff --git a/modules/client/rooms/rooms.cc b/modules/client/rooms/rooms.cc
index 2eba52974..253299c13 100644
--- a/modules/client/rooms/rooms.cc
+++ b/modules/client/rooms/rooms.cc
@@ -96,7 +96,10 @@ put_rooms(client &client, const resource::request &request)
 	if(cmd == "typing")
 		return put__typing(client, request, room_id);
 
-	throw m::NOT_FOUND{"/rooms command not found"};
+	throw m::NOT_FOUND
+	{
+		"/rooms command not found"
+	};
 }
 
 resource::method
@@ -137,9 +140,9 @@ post_rooms(client &client,
 	if(cmd == "join")
 		return post__join(client, request, room_id);
 
-	throw m::error
+	throw m::NOT_FOUND
 	{
-		http::MULTIPLE_CHOICES, "M_NOT_FOUND", "/rooms command required"
+		"/rooms command not found"
 	};
 }
 
diff --git a/modules/client/user/filter.cc b/modules/client/user/filter.cc
index e5bb5bef6..5f52cabd2 100644
--- a/modules/client/user/filter.cc
+++ b/modules/client/user/filter.cc
@@ -46,7 +46,7 @@ post__filter(client &client,
 	// (5.2) Required. The id of the user uploading the filter. The access
 	// token must be authorized to make requests for this user id.
 	if(user_id != request.user_id)
-		throw m::ACCESS_DENIED
+		throw m::FORBIDDEN
 		{
 			"Trying to post a filter for `%s' but you are `%s'",
 			user_id,