diff --git a/schemas/fsssignaldiscovered-v1.0.json b/schemas/fsssignaldiscovered-v1.0.json
index 2664989..18f8fef 100644
--- a/schemas/fsssignaldiscovered-v1.0.json
+++ b/schemas/fsssignaldiscovered-v1.0.json
@@ -61,7 +61,7 @@
                     "minItems": 1,
                     "items": {
                         "type": "object",
-                        "required": ["SignalName"],
+                        "required": ["timestamp", "SignalName"],
                         "description": "Single FSSSignalDiscovered event",
                         "properties": {
                             "timestamp": {