diff --git a/data/event-schemas/schema/m.call.answer.yaml b/data/event-schemas/schema/m.call.answer.yaml
index be978387..d6caddc5 100644
--- a/data/event-schemas/schema/m.call.answer.yaml
+++ b/data/event-schemas/schema/m.call.answer.yaml
@@ -38,7 +38,7 @@
                     "description": "This identifies the party that sent this event. A client may choose to re-use the device ID from end-to-end cryptography for the value of this field. "
                 }
             },
-            "required": ["call_id", "answer", "version"]
+            "required": ["call_id", "answer", "version", "party_id"]
         },
         "type": {
             "type": "string",
diff --git a/data/event-schemas/schema/m.call.candidates.yaml b/data/event-schemas/schema/m.call.candidates.yaml
index dc328b95..2d5c5501 100644
--- a/data/event-schemas/schema/m.call.candidates.yaml
+++ b/data/event-schemas/schema/m.call.candidates.yaml
@@ -44,7 +44,7 @@
                     "description": "The version of the VoIP specification this message adheres to. This specification is version 1. This field is a string such that experimental implementations can use non-integer versions. This field was an integer in the previous spec version and implementations must accept an integer 0."
                 }
             },
-            "required": ["call_id", "candidates", "version"]
+            "required": ["call_id", "candidates", "version", "party_id"]
         },
         "type": {
             "type": "string",
diff --git a/data/event-schemas/schema/m.call.hangup.yaml b/data/event-schemas/schema/m.call.hangup.yaml
index da871d36..f89b4b6b 100644
--- a/data/event-schemas/schema/m.call.hangup.yaml
+++ b/data/event-schemas/schema/m.call.hangup.yaml
@@ -29,7 +29,7 @@
                     ]
                 }
             },
-            "required": ["call_id", "version"]
+            "required": ["call_id", "version", "party_id"]
         },
         "type": {
             "type": "string",