diff --git a/modules/federation/backfill.cc b/modules/federation/backfill.cc
index b88d6ffdf..7cf7ced06 100644
--- a/modules/federation/backfill.cc
+++ b/modules/federation/backfill.cc
@@ -67,6 +67,12 @@ resource::response
 get__backfill(client &client,
               const resource::request &request)
 {
+	if(request.parv.size() < 1)
+		throw m::NEED_MORE_PARAMS
+		{
+			"room_id path parameter required"
+		};
+
 	m::room::id::buf room_id
 	{
 		url::decode(room_id, request.parv[0])
diff --git a/modules/federation/backfill_ids.cc b/modules/federation/backfill_ids.cc
index f229f9b50..d3801a7f4 100644
--- a/modules/federation/backfill_ids.cc
+++ b/modules/federation/backfill_ids.cc
@@ -63,6 +63,12 @@ resource::response
 get__backfill_ids(client &client,
                   const resource::request &request)
 {
+	if(request.parv.size() < 1)
+		throw m::NEED_MORE_PARAMS
+		{
+			"room_id path parameter required"
+		};
+
 	m::room::id::buf room_id
 	{
 		url::decode(room_id, request.parv[0])
diff --git a/modules/federation/event.cc b/modules/federation/event.cc
index 1573bac69..b8d49dcbe 100644
--- a/modules/federation/event.cc
+++ b/modules/federation/event.cc
@@ -33,6 +33,12 @@ resource::response
 handle_get(client &client,
            const resource::request &request)
 {
+	if(request.parv.size() < 1)
+		throw m::NEED_MORE_PARAMS
+		{
+			"event_id path parameter required."
+		};
+
 	m::event::id::buf event_id
 	{
 		url::decode(event_id, request.parv[0])
diff --git a/modules/federation/send.cc b/modules/federation/send.cc
index 32cc3f4cf..3acb26aea 100644
--- a/modules/federation/send.cc
+++ b/modules/federation/send.cc
@@ -93,6 +93,12 @@ resource::response
 handle_put(client &client,
            const resource::request::object<m::txn> &request)
 {
+	if(request.parv.size() < 1)
+		throw m::NEED_MORE_PARAMS
+		{
+			"txn_id path parameter required"
+		};
+
 	const auto txn_id
 	{
 		request.parv[0]
diff --git a/modules/federation/state.cc b/modules/federation/state.cc
index 7dbe51c52..dd79517bb 100644
--- a/modules/federation/state.cc
+++ b/modules/federation/state.cc
@@ -37,6 +37,12 @@ resource::response
 get__state(client &client,
            const resource::request &request)
 {
+	if(request.parv.size() < 1)
+		throw m::NEED_MORE_PARAMS
+		{
+			"room_id path parameter required"
+		};
+
 	m::room::id::buf room_id
 	{
 		url::decode(room_id, request.parv[0])
diff --git a/modules/federation/state_ids.cc b/modules/federation/state_ids.cc
index ae063ef2e..fde175b31 100644
--- a/modules/federation/state_ids.cc
+++ b/modules/federation/state_ids.cc
@@ -30,6 +30,12 @@ resource::response
 get__state_ids(client &client,
                const resource::request &request)
 {
+	if(request.parv.size() < 1)
+		throw m::NEED_MORE_PARAMS
+		{
+			"room_id path parameter required"
+		};
+
 	m::room::id::buf room_id
 	{
 		url::decode(room_id, request.parv[0])
diff --git a/modules/federation/user_devices.cc b/modules/federation/user_devices.cc
index 452db5878..d66627bb0 100644
--- a/modules/federation/user_devices.cc
+++ b/modules/federation/user_devices.cc
@@ -51,7 +51,7 @@ get__user_devices(client &client,
 
 	m::user::id::buf user_id
 	{
-		url::decode(user_id, request.parv[1])
+		url::decode(user_id, request.parv[0])
 	};
 
 	return resource::response