diff --git a/sentry_sdk/integrations/asgi.py b/sentry_sdk/integrations/asgi.py
index 61bc20fd40..f67c47ef02 100644
--- a/sentry_sdk/integrations/asgi.py
+++ b/sentry_sdk/integrations/asgi.py
@@ -176,6 +176,18 @@ async def _run_app(self, scope, receive, send, asgi_version):
         _asgi_middleware_applied.set(True)
         try:
             with sentry_sdk.isolation_scope() as sentry_scope:
+                (
+                    transaction_name,
+                    transaction_source,
+                ) = self._get_transaction_name_and_source(
+                    self.transaction_style,
+                    scope,
+                )
+                sentry_scope.set_transaction_name(
+                    transaction_name,
+                    source=transaction_source,
+                )
+
                 with track_session(sentry_scope, session_mode="request"):
                     sentry_scope.clear_breadcrumbs()
                     sentry_scope._name = "asgi"
@@ -183,19 +195,12 @@ async def _run_app(self, scope, receive, send, asgi_version):
                     sentry_scope.add_event_processor(processor)
 
                     ty = scope["type"]
-                    (
-                        transaction_name,
-                        transaction_source,
-                    ) = self._get_transaction_name_and_source(
-                        self.transaction_style,
-                        scope,
-                    )
 
                     method = scope.get("method", "").upper()
                     should_trace = method in self.http_methods_to_capture
                     with sentry_sdk.continue_trace(_get_headers(scope)):
                         with (
-                            sentry_sdk.start_transaction(
+                            sentry_sdk.start_span(
                                 op=(
                                     OP.WEBSOCKET_SERVER
                                     if ty == "websocket"
@@ -251,13 +256,18 @@ def event_processor(self, event, hint, asgi_scope):
         event["request"] = deepcopy(request_data)
 
         # Only set transaction name if not already set by Starlette or FastAPI (or other frameworks)
-        already_set = event["transaction"] != _DEFAULT_TRANSACTION_NAME and event[
-            "transaction_info"
-        ].get("source") in [
-            TRANSACTION_SOURCE_COMPONENT,
-            TRANSACTION_SOURCE_ROUTE,
-            TRANSACTION_SOURCE_CUSTOM,
-        ]
+        already_set = (
+            "transaction" in event
+            and event["transaction"] != _DEFAULT_TRANSACTION_NAME
+            and "transaction_info" in event
+            and "source" in event["transaction_info"]
+            and event["transaction_info"]["source"]
+            in [
+                TRANSACTION_SOURCE_COMPONENT,
+                TRANSACTION_SOURCE_ROUTE,
+                TRANSACTION_SOURCE_CUSTOM,
+            ]
+        )
         if not already_set:
             name, source = self._get_transaction_name_and_source(
                 self.transaction_style, asgi_scope
diff --git a/sentry_sdk/integrations/wsgi.py b/sentry_sdk/integrations/wsgi.py
index 72ecfdb758..3aebff17d5 100644
--- a/sentry_sdk/integrations/wsgi.py
+++ b/sentry_sdk/integrations/wsgi.py
@@ -98,7 +98,9 @@ def __call__(self, environ, start_response):
         _wsgi_middleware_applied.set(True)
         try:
             with sentry_sdk.isolation_scope() as scope:
-                scope.set_transaction_name(DEFAULT_TRANSACTION_NAME, source=TRANSACTION_SOURCE_ROUTE)
+                scope.set_transaction_name(
+                    DEFAULT_TRANSACTION_NAME, source=TRANSACTION_SOURCE_ROUTE
+                )
 
                 with track_session(scope, session_mode="request"):
                     with capture_internal_exceptions():
diff --git a/sentry_sdk/tracing.py b/sentry_sdk/tracing.py
index 31312c9ad3..c2bd5734c5 100644
--- a/sentry_sdk/tracing.py
+++ b/sentry_sdk/tracing.py
@@ -683,9 +683,9 @@ def get_trace_context(self):
             rv["status"] = self.status
 
         if self.containing_transaction:
-            rv["dynamic_sampling_context"] = (
-                self.containing_transaction.get_baggage().dynamic_sampling_context()
-            )
+            rv[
+                "dynamic_sampling_context"
+            ] = self.containing_transaction.get_baggage().dynamic_sampling_context()
 
         data = {}
 
@@ -1203,6 +1203,7 @@ def __init__(
         start_timestamp=None,  # type: Optional[Union[datetime, float]]
         origin=None,  # type: Optional[str]
         name=None,  # type: Optional[str]
+        source=TRANSACTION_SOURCE_CUSTOM,  # type: str
         otel_span=None,  # type: Optional[OtelSpan]
         **_,  # type: dict[str, object]
     ):
@@ -1232,6 +1233,7 @@ def __init__(
             self.op = op
             self.description = description
             self.name = span_name
+            self.source = source
 
             if status is not None:
                 self.set_status(status)