diff --git a/aws_lambda_powertools/utilities/data_classes/api_gateway_authorizer_event.py b/aws_lambda_powertools/utilities/data_classes/api_gateway_authorizer_event.py
index 073789eabe6..b87c8ddaf20 100644
--- a/aws_lambda_powertools/utilities/data_classes/api_gateway_authorizer_event.py
+++ b/aws_lambda_powertools/utilities/data_classes/api_gateway_authorizer_event.py
@@ -167,7 +167,7 @@ def get_header_value(
         self,
         name: str,
         default_value: str,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> str: ...
 
     @overload
@@ -175,14 +175,14 @@ def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]: ...
 
     def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]:
         """Get header value by name
 
@@ -291,14 +291,14 @@ def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]: ...
 
     def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]:
         """Get header value by name
 
diff --git a/aws_lambda_powertools/utilities/data_classes/appsync_resolver_event.py b/aws_lambda_powertools/utilities/data_classes/appsync_resolver_event.py
index edb590e7770..f58308377ff 100644
--- a/aws_lambda_powertools/utilities/data_classes/appsync_resolver_event.py
+++ b/aws_lambda_powertools/utilities/data_classes/appsync_resolver_event.py
@@ -219,7 +219,7 @@ def get_header_value(
         self,
         name: str,
         default_value: str,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> str: ...
 
     @overload
@@ -227,14 +227,14 @@ def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]: ...
 
     def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]:
         """Get header value by name
 
diff --git a/aws_lambda_powertools/utilities/data_classes/common.py b/aws_lambda_powertools/utilities/data_classes/common.py
index 5956a6cbdfd..b78a6e4939c 100644
--- a/aws_lambda_powertools/utilities/data_classes/common.py
+++ b/aws_lambda_powertools/utilities/data_classes/common.py
@@ -228,7 +228,7 @@ def get_header_value(
         self,
         name: str,
         default_value: str,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> str: ...
 
     @overload
@@ -236,14 +236,14 @@ def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]: ...
 
     def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]:
         """Get header value by name
 
diff --git a/aws_lambda_powertools/utilities/data_classes/s3_object_event.py b/aws_lambda_powertools/utilities/data_classes/s3_object_event.py
index 4338a2f61e7..dc79b72766f 100644
--- a/aws_lambda_powertools/utilities/data_classes/s3_object_event.py
+++ b/aws_lambda_powertools/utilities/data_classes/s3_object_event.py
@@ -78,7 +78,7 @@ def get_header_value(
         self,
         name: str,
         default_value: str,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> str: ...
 
     @overload
@@ -86,14 +86,14 @@ def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]: ...
 
     def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]:
         """Get header value by name
 
diff --git a/aws_lambda_powertools/utilities/data_classes/shared_functions.py b/aws_lambda_powertools/utilities/data_classes/shared_functions.py
index 2df833e54e8..0e88a5dac93 100644
--- a/aws_lambda_powertools/utilities/data_classes/shared_functions.py
+++ b/aws_lambda_powertools/utilities/data_classes/shared_functions.py
@@ -26,7 +26,7 @@ def get_header_value(
     headers: dict[str, Any],
     name: str,
     default_value: str,
-    case_sensitive: bool | None = False,
+    case_sensitive: bool = False,
 ) -> str: ...
 
 
@@ -35,7 +35,7 @@ def get_header_value(
     headers: dict[str, Any],
     name: str,
     default_value: str | None = None,
-    case_sensitive: bool | None = False,
+    case_sensitive: bool = False,
 ) -> str | None: ...
 
 
@@ -43,7 +43,7 @@ def get_header_value(
     headers: dict[str, Any],
     name: str,
     default_value: str | None = None,
-    case_sensitive: bool | None = False,
+    case_sensitive: bool = False,
 ) -> str | None:
     """
     Get the value of a header by its name.
diff --git a/aws_lambda_powertools/utilities/data_classes/vpc_lattice.py b/aws_lambda_powertools/utilities/data_classes/vpc_lattice.py
index e2612e0334f..3fe9762fcd7 100644
--- a/aws_lambda_powertools/utilities/data_classes/vpc_lattice.py
+++ b/aws_lambda_powertools/utilities/data_classes/vpc_lattice.py
@@ -78,7 +78,7 @@ def get_header_value(
         self,
         name: str,
         default_value: str,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> str: ...
 
     @overload
@@ -86,14 +86,14 @@ def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]: ...
 
     def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
-        case_sensitive: Optional[bool] = False,
+        case_sensitive: bool = False,
     ) -> Optional[str]:
         """Get header value by name