diff --git a/ddtrace/appsec/_ddwaf/ddwaf_types.py b/ddtrace/appsec/_ddwaf/ddwaf_types.py
index 607788069a1..c7a00600ca2 100644
--- a/ddtrace/appsec/_ddwaf/ddwaf_types.py
+++ b/ddtrace/appsec/_ddwaf/ddwaf_types.py
@@ -105,7 +105,7 @@ class ddwaf_object(ctypes.Structure):
 
     def __init__(
         self,
-        struct: DDWafRulesType = None,
+        struct: Optional[DDWafRulesType] = None,
         observator: _observator = _observator(),  # noqa : B008
         max_objects: int = DDWAF_MAX_CONTAINER_SIZE,
         max_depth: int = DDWAF_MAX_CONTAINER_DEPTH,
diff --git a/ddtrace/appsec/_ddwaf/waf.py b/ddtrace/appsec/_ddwaf/waf.py
index 66e89a75252..002cc8b1372 100644
--- a/ddtrace/appsec/_ddwaf/waf.py
+++ b/ddtrace/appsec/_ddwaf/waf.py
@@ -172,7 +172,7 @@ def run(
         self,
         ctx: ddwaf_context_capsule,
         data: DDWafRulesType,
-        ephemeral_data: DDWafRulesType = None,
+        ephemeral_data: Optional[DDWafRulesType] = None,
         timeout_ms: float = DEFAULT.WAF_TIMEOUT,
     ) -> DDWaf_result:
         start = time.monotonic()
diff --git a/ddtrace/appsec/_ddwaf/waf_mock.py b/ddtrace/appsec/_ddwaf/waf_mock.py
index 46a97ed1595..f27fb7e3cdb 100644
--- a/ddtrace/appsec/_ddwaf/waf_mock.py
+++ b/ddtrace/appsec/_ddwaf/waf_mock.py
@@ -1,5 +1,6 @@
 from typing import Any
 from typing import Dict
+from typing import Optional
 from typing import Sequence
 from typing import Tuple
 
@@ -41,7 +42,7 @@ def run(
         self,
         ctx: ddwaf_context_capsule,
         data: DDWafRulesType,
-        ephemeral_data: DDWafRulesType = None,
+        ephemeral_data: Optional[DDWafRulesType] = None,
         timeout_ms: float = DEFAULT.WAF_TIMEOUT,
     ) -> DDWaf_result:
         LOGGER.debug("DDWaf features disabled. dry run")
diff --git a/ddtrace/appsec/_ddwaf/waf_stubs.py b/ddtrace/appsec/_ddwaf/waf_stubs.py
index 70b0d89478b..1e9fb694660 100644
--- a/ddtrace/appsec/_ddwaf/waf_stubs.py
+++ b/ddtrace/appsec/_ddwaf/waf_stubs.py
@@ -110,7 +110,7 @@ def run(
         self,
         ctx: ddwaf_context_capsule,
         data: DDWafRulesType,
-        ephemeral_data: DDWafRulesType = None,
+        ephemeral_data: Optional[DDWafRulesType] = None,
         timeout_ms: float = DEFAULT.WAF_TIMEOUT,
     ) -> DDWaf_result:
         pass
diff --git a/ddtrace/contrib/internal/unittest/patch.py b/ddtrace/contrib/internal/unittest/patch.py
index 37c3dff14e9..76a9552ebcf 100644
--- a/ddtrace/contrib/internal/unittest/patch.py
+++ b/ddtrace/contrib/internal/unittest/patch.py
@@ -1,6 +1,7 @@
 import inspect
 import os
 from typing import Dict
+from typing import Optional
 from typing import Union
 import unittest
 
@@ -464,7 +465,7 @@ def unpatch():
     _CIVisibility.disable()
 
 
-def _set_test_span_status(test_item, status: str, exc_info: str = None, skip_reason: str = None):
+def _set_test_span_status(test_item, status: str, exc_info: Optional[str] = None, skip_reason: Optional[str] = None):
     span = _extract_span(test_item)
     if not span:
         log.debug("Tried setting test result for test but could not find span for %s", test_item)
diff --git a/ddtrace/internal/telemetry/metrics_namespaces.pyi b/ddtrace/internal/telemetry/metrics_namespaces.pyi
index 738a0455b17..1d68fd41279 100644
--- a/ddtrace/internal/telemetry/metrics_namespaces.pyi
+++ b/ddtrace/internal/telemetry/metrics_namespaces.pyi
@@ -20,5 +20,5 @@ class MetricNamespace:
         namespace: TELEMETRY_NAMESPACE,
         name: str,
         value: float = 1.0,
-        tags: MetricTagType = None,
+        tags: Optional[MetricTagType] = None,
     ) -> None: ...
diff --git a/ddtrace/internal/telemetry/writer.py b/ddtrace/internal/telemetry/writer.py
index c974330a247..e36fcfa3320 100644
--- a/ddtrace/internal/telemetry/writer.py
+++ b/ddtrace/internal/telemetry/writer.py
@@ -560,7 +560,9 @@ def _format_file_path(self, filename: str) -> str:
         except ValueError:
             return filename
 
-    def add_gauge_metric(self, namespace: TELEMETRY_NAMESPACE, name: str, value: float, tags: MetricTagType = None):
+    def add_gauge_metric(
+        self, namespace: TELEMETRY_NAMESPACE, name: str, value: float, tags: Optional[MetricTagType] = None
+    ):
         """
         Queues gauge metric
         """
@@ -573,7 +575,9 @@ def add_gauge_metric(self, namespace: TELEMETRY_NAMESPACE, name: str, value: flo
                 tags,
             )
 
-    def add_rate_metric(self, namespace: TELEMETRY_NAMESPACE, name: str, value: float, tags: MetricTagType = None):
+    def add_rate_metric(
+        self, namespace: TELEMETRY_NAMESPACE, name: str, value: float, tags: Optional[MetricTagType] = None
+    ):
         """
         Queues rate metric
         """
@@ -586,7 +590,9 @@ def add_rate_metric(self, namespace: TELEMETRY_NAMESPACE, name: str, value: floa
                 tags,
             )
 
-    def add_count_metric(self, namespace: TELEMETRY_NAMESPACE, name: str, value: int = 1, tags: MetricTagType = None):
+    def add_count_metric(
+        self, namespace: TELEMETRY_NAMESPACE, name: str, value: int = 1, tags: Optional[MetricTagType] = None
+    ):
         """
         Queues count metric
         """
@@ -600,7 +606,7 @@ def add_count_metric(self, namespace: TELEMETRY_NAMESPACE, name: str, value: int
             )
 
     def add_distribution_metric(
-        self, namespace: TELEMETRY_NAMESPACE, name: str, value: float, tags: MetricTagType = None
+        self, namespace: TELEMETRY_NAMESPACE, name: str, value: float, tags: Optional[MetricTagType] = None
     ):
         """
         Queues distributions metric
diff --git a/mypy.ini b/mypy.ini
index a0b48ad667f..882598d8256 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -7,7 +7,6 @@ scripts_are_modules = true
 show_error_codes = true
 warn_unused_ignores = true
 warn_unused_configs = true
-no_implicit_optional = true
 ignore_missing_imports = true
 namespace_packages = true
 plugins = envier.mypy
diff --git a/tests/appsec/integrations/fastapi_tests/test_fastapi_appsec_iast.py b/tests/appsec/integrations/fastapi_tests/test_fastapi_appsec_iast.py
index 09261f1bf0e..5d80bc11646 100644
--- a/tests/appsec/integrations/fastapi_tests/test_fastapi_appsec_iast.py
+++ b/tests/appsec/integrations/fastapi_tests/test_fastapi_appsec_iast.py
@@ -283,7 +283,7 @@ async def test_route(request: Request):
 @pytest.mark.skipif(fastapi_version < (0, 95, 0), reason="Header annotation doesn't work on fastapi 94 or lower")
 def test_header_value_source_typing_param(fastapi_application, client, tracer, test_spans):
     @fastapi_application.get("/index.html")
-    async def test_route(iast_header: typing.Annotated[str, Header()] = None):
+    async def test_route(iast_header: typing.Annotated[str, Header()]):
         from ddtrace.appsec._iast._taint_tracking import origin_to_str
         from ddtrace.appsec._iast._taint_tracking._taint_objects_base import get_tainted_ranges
 
diff --git a/tests/ci_visibility/api_client/_util.py b/tests/ci_visibility/api_client/_util.py
index 99e57fe9624..f9277931811 100644
--- a/tests/ci_visibility/api_client/_util.py
+++ b/tests/ci_visibility/api_client/_util.py
@@ -176,7 +176,7 @@ def _get_test_client(
         self,
         itr_skipping_level: ITR_SKIPPING_LEVEL = ITR_SKIPPING_LEVEL.TEST,
         requests_mode: REQUESTS_MODE = _AGENTLESS,
-        git_data: GitData = None,
+        git_data: t.Optional[GitData] = None,
         api_key: t.Optional[str] = "my_api_key",
         dd_site: t.Optional[str] = None,
         agentless_url: t.Optional[str] = None,
@@ -215,7 +215,7 @@ def _get_test_client(
     def _get_expected_do_request_setting_payload(
         self,
         itr_skipping_level: ITR_SKIPPING_LEVEL = ITR_SKIPPING_LEVEL.TEST,
-        git_data: GitData = None,
+        git_data: t.Optional[GitData] = None,
         dd_service: t.Optional[str] = None,
         dd_env: t.Optional[str] = None,
     ):
@@ -246,7 +246,7 @@ def _get_expected_do_request_setting_payload(
     def _get_expected_do_request_skippable_payload(
         self,
         itr_skipping_level: ITR_SKIPPING_LEVEL = ITR_SKIPPING_LEVEL.TEST,
-        git_data: GitData = None,
+        git_data: t.Optional[GitData] = None,
         dd_service: t.Optional[str] = None,
         dd_env: t.Optional[str] = None,
     ):
@@ -275,7 +275,7 @@ def _get_expected_do_request_skippable_payload(
 
     def _get_expected_do_request_tests_payload(
         self,
-        repository_url: str = None,
+        repository_url: t.Optional[str] = None,
         dd_service: t.Optional[str] = None,
         dd_env: t.Optional[str] = None,
     ):
diff --git a/tests/contrib/integration_registry/registry_update_helpers/integration.py b/tests/contrib/integration_registry/registry_update_helpers/integration.py
index d837bf1207b..7b250d32e37 100644
--- a/tests/contrib/integration_registry/registry_update_helpers/integration.py
+++ b/tests/contrib/integration_registry/registry_update_helpers/integration.py
@@ -1,3 +1,6 @@
+from typing import Optional
+
+
 class Integration:
     """
     Represents an integration in the registry.
@@ -7,8 +10,8 @@ def __init__(
         self,
         integration_name: str,
         is_external_package: bool = True,
-        dependency_names: list = None,
-        tested_versions_by_dependency: dict = None,
+        dependency_names: Optional[list] = None,
+        tested_versions_by_dependency: Optional[dict] = None,
         is_tested: bool = True,
     ):
         self.integration_name = integration_name
@@ -84,7 +87,7 @@ def should_update(self, new_dependency_versions: dict) -> bool:
                 return True
         return False
 
-    def update(self, updates: dict, update_versions: bool = False, riot_venv: str = None) -> bool:
+    def update(self, updates: dict, update_versions: bool = False, riot_venv: Optional[str] = None) -> bool:
         """Updates the integration with the new dependency versions."""
         # skip if the integration is not an external package
         if not self.is_external_package:
diff --git a/tests/contrib/openai_agents/test_openai_agents_llmobs.py b/tests/contrib/openai_agents/test_openai_agents_llmobs.py
index 3e763d2ae65..588b0e925b0 100644
--- a/tests/contrib/openai_agents/test_openai_agents_llmobs.py
+++ b/tests/contrib/openai_agents/test_openai_agents_llmobs.py
@@ -1,5 +1,6 @@
 from typing import Dict
 from typing import List
+from typing import Optional
 from typing import Tuple
 
 import mock
@@ -122,9 +123,9 @@ def _assert_expected_agent_run(
     expected_span_names: List[str],
     spans,
     llmobs_events,
-    llm_calls: List[Tuple[List[Dict], List[Dict]]] = None,
-    tool_calls: List[dict] = None,
-    previous_tool_events: List[dict] = None,
+    llm_calls: Optional[List[Tuple[List[Dict], List[Dict]]]] = None,
+    tool_calls: Optional[List[dict]] = None,
+    previous_tool_events: Optional[List[dict]] = None,
     is_chat=False,
 ) -> List[dict]:
     """Assert expected LLMObs events matches actual events for an agent run
diff --git a/tests/contrib/pytest/test_pytest.py b/tests/contrib/pytest/test_pytest.py
index 9907b6a7398..44dc5e8e224 100644
--- a/tests/contrib/pytest/test_pytest.py
+++ b/tests/contrib/pytest/test_pytest.py
@@ -48,7 +48,7 @@
 def _get_spans_from_list(
     spans: t.List[ddtrace.trace.Span],
     span_type: str,
-    name: str = None,
+    name: t.Optional[str] = None,
     status: t.Optional[str] = None,
 ) -> t.List[ddtrace.trace.Span]:
     _names_map = {