diff --git a/sentry_sdk/tracing.py b/sentry_sdk/tracing.py
index c56a7e729c..00fe816e8f 100644
--- a/sentry_sdk/tracing.py
+++ b/sentry_sdk/tracing.py
@@ -183,16 +183,22 @@ def __init__(
         only_if_parent=False,  # type: bool
         parent_span=None,  # type: Optional[Span]
         otel_span=None,  # type: Optional[OtelSpan]
+        span=None,  # type: Optional[Span]
     ):
         # type: (...) -> None
         """
         If otel_span is passed explicitly, just acts as a proxy.
 
+        If span is passed explicitly, use it. The only purpose of this param
+        if backwards compatibility with start_transaction(transaction=...).
+
         If only_if_parent is True, just return an INVALID_SPAN
         and avoid instrumentation if there's no active parent span.
         """
         if otel_span is not None:
             self._otel_span = otel_span
+        elif span is not None:
+            self._otel_span = span._otel_span
         else:
             skip_span = False
             if only_if_parent and parent_span is None:
diff --git a/tests/integrations/logging/test_logging.py b/tests/integrations/logging/test_logging.py
index e1b24a9853..e54fd829f1 100644
--- a/tests/integrations/logging/test_logging.py
+++ b/tests/integrations/logging/test_logging.py
@@ -296,7 +296,10 @@ def test_ignore_logger_wildcard(sentry_init, capture_events):
 
 def test_logging_dictionary_interpolation(sentry_init, capture_events):
     """Here we test an entire dictionary being interpolated into the log message."""
-    sentry_init(integrations=[LoggingIntegration()], default_integrations=False)
+    sentry_init(
+        integrations=[LoggingIntegration(event_level=logging.ERROR)],
+        default_integrations=False,
+    )
     events = capture_events()
 
     logger.error("this is a log with a dictionary %s", {"foo": "bar"})
@@ -312,7 +315,10 @@ def test_logging_dictionary_interpolation(sentry_init, capture_events):
 
 def test_logging_dictionary_args(sentry_init, capture_events):
     """Here we test items from a dictionary being interpolated into the log message."""
-    sentry_init(integrations=[LoggingIntegration()], default_integrations=False)
+    sentry_init(
+        integrations=[LoggingIntegration(event_level=logging.ERROR)],
+        default_integrations=False,
+    )
     events = capture_events()
 
     logger.error(
diff --git a/tests/integrations/threading/test_threading.py b/tests/integrations/threading/test_threading.py
index b1770874e5..11b4ee5301 100644
--- a/tests/integrations/threading/test_threading.py
+++ b/tests/integrations/threading/test_threading.py
@@ -104,7 +104,6 @@ def double(number):
         assert len(event["spans"]) == 0
 
 
-@pytest.mark.skip(reason="Temporarily disable to release SDK 2.0a1.")
 def test_circular_references(sentry_init, request):
     sentry_init(default_integrations=False, integrations=[ThreadingIntegration()])
 
@@ -232,7 +231,7 @@ def do_some_work(number):
 
     threads = []
 
-    with sentry_sdk.start_transaction(op="outer-trx"):
+    with sentry_sdk.start_span(op="outer-trx"):
         for number in range(5):
             with sentry_sdk.start_span(
                 op=f"outer-submit-{number}", name="Thread: main"
diff --git a/tests/opentelemetry/test_compat.py b/tests/opentelemetry/test_compat.py
index 1ae73494cd..381d9ad22e 100644
--- a/tests/opentelemetry/test_compat.py
+++ b/tests/opentelemetry/test_compat.py
@@ -1,4 +1,5 @@
 import sentry_sdk
+from sentry_sdk.tracing import Transaction
 
 
 def test_transaction_name_span_description_compat(
@@ -52,3 +53,47 @@ def test_transaction_name_span_description_compat(
     assert span["op"] == "span-op"
     assert span["data"]["sentry.op"] == "span-op"
     assert span["data"]["sentry.description"] == "span-desc"
+
+
+def test_start_transaction_compat(
+    sentry_init,
+    capture_events,
+):
+    sentry_init(traces_sample_rate=1.0)
+
+    events = capture_events()
+
+    with sentry_sdk.start_transaction(
+        name="trx-name",
+        op="trx-op",
+    ):
+        ...
+
+    transaction = events[0]
+    assert transaction["transaction"] == "trx-name"
+    assert transaction["contexts"]["trace"]["op"] == "trx-op"
+    assert transaction["contexts"]["trace"]["data"]["sentry.op"] == "trx-op"
+    assert transaction["contexts"]["trace"]["data"]["sentry.name"] == "trx-name"
+    assert "sentry.description" not in transaction["contexts"]["trace"]["data"]
+
+
+def test_start_transaction_with_explicit_transaction_compat(
+    sentry_init,
+    capture_events,
+):
+    """It should still be possible to provide a ready-made Transaction to start_transaction."""
+    sentry_init(traces_sample_rate=1.0)
+
+    events = capture_events()
+
+    transaction = Transaction(name="trx-name", op="trx-op")
+
+    with sentry_sdk.start_transaction(transaction=transaction):
+        pass
+
+    transaction = events[0]
+    assert transaction["transaction"] == "trx-name"
+    assert transaction["contexts"]["trace"]["op"] == "trx-op"
+    assert transaction["contexts"]["trace"]["data"]["sentry.op"] == "trx-op"
+    assert transaction["contexts"]["trace"]["data"]["sentry.name"] == "trx-name"
+    assert "sentry.description" not in transaction["contexts"]["trace"]["data"]