diff --git a/logfire/_internal/config.py b/logfire/_internal/config.py
index a560b2f19..753b8b70b 100644
--- a/logfire/_internal/config.py
+++ b/logfire/_internal/config.py
@@ -578,6 +578,9 @@ def _load_configuration(
         if isinstance(advanced, dict):
             # This is particularly for deserializing from a dict as in executors.py
             advanced = AdvancedOptions(**advanced)  # type: ignore
+            id_generator = advanced.id_generator
+            if isinstance(id_generator, dict) and list(id_generator.keys()) == ['seed']:  # type: ignore  # pragma: no branch
+                advanced.id_generator = SeededRandomIdGenerator(**id_generator)  # type: ignore
         elif advanced is None:
             advanced = AdvancedOptions(base_url=param_manager.load_param('base_url'))
         self.advanced = advanced
diff --git a/logfire/_internal/integrations/executors.py b/logfire/_internal/integrations/executors.py
index e4a7c31f1..5176593e9 100644
--- a/logfire/_internal/integrations/executors.py
+++ b/logfire/_internal/integrations/executors.py
@@ -63,6 +63,7 @@ def serialize_config() -> dict[str, Any]:
 
 
 def deserialize_config(config: dict[str, Any]) -> None:
-    from ..config import configure
+    from ..config import GLOBAL_CONFIG, configure
 
-    configure(**config)
+    if not GLOBAL_CONFIG._initialized:  # type: ignore
+        configure(**config)
diff --git a/tests/test_configure.py b/tests/test_configure.py
index ee4484b0e..40e6276a2 100644
--- a/tests/test_configure.py
+++ b/tests/test_configure.py
@@ -52,7 +52,7 @@
 from logfire._internal.exporters.wrapper import WrapperSpanExporter
 from logfire._internal.integrations.executors import deserialize_config, serialize_config
 from logfire._internal.tracer import PendingSpanProcessor
-from logfire._internal.utils import get_version
+from logfire._internal.utils import SeededRandomIdGenerator, get_version
 from logfire.exceptions import LogfireConfigError
 from logfire.integrations.pydantic import get_pydantic_plugin_config
 from logfire.testing import TestExporter
@@ -848,14 +848,13 @@ def test_config_serializable():
         )
 
     serialized = serialize_config()
+    GLOBAL_CONFIG._initialized = False  # type: ignore  # ensure deserialize_config actually configures
     deserialize_config(serialized)
     serialized2 = serialize_config()
 
     def normalize(s: dict[str, Any]) -> dict[str, Any]:
         for value in s.values():
             assert not dataclasses.is_dataclass(value)
-        # This gets deepcopied by dataclasses.asdict, so we can't compare them directly
-        del s['advanced']['id_generator']
         return s
 
     assert normalize(serialized) == normalize(serialized2)
@@ -864,6 +863,7 @@ def normalize(s: dict[str, Any]) -> dict[str, Any]:
     assert isinstance(GLOBAL_CONFIG.sampling, logfire.SamplingOptions)
     assert isinstance(GLOBAL_CONFIG.scrubbing, logfire.ScrubbingOptions)
     assert isinstance(GLOBAL_CONFIG.advanced, logfire.AdvancedOptions)
+    assert isinstance(GLOBAL_CONFIG.advanced.id_generator, SeededRandomIdGenerator)
 
 
 def test_config_serializable_console_false():