diff --git a/sentry_sdk/opentelemetry/span_processor.py b/sentry_sdk/opentelemetry/span_processor.py
index 16d2f9e6b3..a5dc2e23a7 100644
--- a/sentry_sdk/opentelemetry/span_processor.py
+++ b/sentry_sdk/opentelemetry/span_processor.py
@@ -225,6 +225,7 @@ def _root_span_to_transaction_event(self, span: ReadableSpan) -> Optional[Event]
         if span.resource.attributes:
             contexts[OTEL_SENTRY_CONTEXT] = {"resource": dict(span.resource.attributes)}
 
+        event.setdefault("tags", {})
         event.update(
             {
                 "type": "transaction",