diff --git a/pydase_service_base/database/__init__.py b/pydase_service_base/database/__init__.py
index 8fc362f..8a3b775 100644
--- a/pydase_service_base/database/__init__.py
+++ b/pydase_service_base/database/__init__.py
@@ -1,47 +1,52 @@
-class OptionalDependencyError(Exception):
-    """Exception raised when an optional dependency is not installed."""
-
-
-try:
-    import influxdb_client  # type: ignore # noqa
+from typing import TYPE_CHECKING
 
+if TYPE_CHECKING:
     from .influxdb_session import InfluxDBSession  # type: ignore
-except ImportError:
-
-    class InfluxDBSession:  # type: ignore
-        def __init__(self) -> None:
-            raise OptionalDependencyError(
-                "InfluxDBSession requires the 'influxdbv2' extra. "
-                "Please refer to https://gitlab.phys.ethz.ch/tiqi-projects/qchub/icon-services/pydase_service_base."
-            )
-
-
-try:
-    import influxdb  # noqa
-
     from .influxdbv1_session import InfluxDBv1Session  # type: ignore
-except ImportError:
-
-    class InfluxDBv1Session:  # type: ignore
-        def __init__(self) -> None:
-            raise OptionalDependencyError(
-                "InfluxDBv1Session requires the 'influxdbv1' extra. "
-                "Please refer to https://gitlab.phys.ethz.ch/tiqi-projects/qchub/icon-services/pydase_service_base."
-            )
-
-
-try:
-    import sqlmodel  # noqa
-
     from .postgres_session import PostgresDatabaseSession  # type: ignore
-except ImportError:
+else:
 
-    class PostgresDatabaseSession:  # type: ignore
-        def __init__(self) -> None:
-            raise OptionalDependencyError(
-                "PostgresDatabaseSession requires the 'postgresql' extra. "
-                "Please refer to https://gitlab.phys.ethz.ch/tiqi-projects/qchub/icon-services/pydase_service_base."
-            )
+    class OptionalDependencyError(Exception):
+        """Exception raised when an optional dependency is not installed."""
+
+    try:
+        import influxdb_client  # type: ignore # noqa
+
+        from .influxdb_session import InfluxDBSession  # type: ignore
+    except ImportError:
+
+        class InfluxDBSession:  # type: ignore
+            def __init__(self) -> None:
+                raise OptionalDependencyError(
+                    "InfluxDBSession requires the 'influxdbv2' extra. "
+                    "Please refer to https://gitlab.phys.ethz.ch/tiqi-projects/qchub/icon-services/pydase_service_base."
+                )
+
+    try:
+        import influxdb  # type: ignore # noqa
+
+        from .influxdbv1_session import InfluxDBv1Session  # type: ignore
+    except ImportError:
+
+        class InfluxDBv1Session:  # type: ignore
+            def __init__(self) -> None:
+                raise OptionalDependencyError(
+                    "InfluxDBv1Session requires the 'influxdbv1' extra. "
+                    "Please refer to https://gitlab.phys.ethz.ch/tiqi-projects/qchub/icon-services/pydase_service_base."
+                )
+
+    try:
+        import sqlmodel  # noqa
+
+        from .postgres_session import PostgresDatabaseSession  # type: ignore
+    except ImportError:
+
+        class PostgresDatabaseSession:  # type: ignore
+            def __init__(self) -> None:
+                raise OptionalDependencyError(
+                    "PostgresDatabaseSession requires the 'postgresql' extra. "
+                    "Please refer to https://gitlab.phys.ethz.ch/tiqi-projects/qchub/icon-services/pydase_service_base."
+                )
 
 
 __all__ = ["InfluxDBSession", "InfluxDBv1Session", "PostgresDatabaseSession"]