diff --git a/openapi_pydantic/v3/v3_0_3/encoding.py b/openapi_pydantic/v3/v3_0_3/encoding.py
index db03480..1cbe6c9 100644
--- a/openapi_pydantic/v3/v3_0_3/encoding.py
+++ b/openapi_pydantic/v3/v3_0_3/encoding.py
@@ -59,7 +59,7 @@ class Encoding(BaseModel):
     the request body media type is not `application/x-www-form-urlencoded`.
     """
 
-    explode: bool = False
+    explode: Optional[bool] = None
     """
     When this is true, property values of type `array` or `object` generate separate 
     parameters for each value of the array, or key-value-pair of the map.
diff --git a/openapi_pydantic/v3/v3_0_3/parameter.py b/openapi_pydantic/v3/v3_0_3/parameter.py
index 239baea..80498ba 100644
--- a/openapi_pydantic/v3/v3_0_3/parameter.py
+++ b/openapi_pydantic/v3/v3_0_3/parameter.py
@@ -115,7 +115,7 @@ class ParameterBase(BaseModel):
     - for `cookie` - `form`.
     """
 
-    explode: bool = False
+    explode: Optional[bool] = None
     """
     When this is true, parameter values of type `array` or `object` generate separate 
     parameters for each value of the array or key-value pair of the map.
diff --git a/openapi_pydantic/v3/v3_1_0/encoding.py b/openapi_pydantic/v3/v3_1_0/encoding.py
index 0af41ce..580d3d1 100644
--- a/openapi_pydantic/v3/v3_1_0/encoding.py
+++ b/openapi_pydantic/v3/v3_1_0/encoding.py
@@ -61,7 +61,7 @@ class Encoding(BaseModel):
     [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored.
     """
 
-    explode: bool = False
+    explode: Optional[bool] = None
     """
     When this is true, property values of type `array` or `object` generate separate 
     parameters for each value of the array, or key-value-pair of the map.
diff --git a/openapi_pydantic/v3/v3_1_0/parameter.py b/openapi_pydantic/v3/v3_1_0/parameter.py
index 416511d..1c7afb5 100644
--- a/openapi_pydantic/v3/v3_1_0/parameter.py
+++ b/openapi_pydantic/v3/v3_1_0/parameter.py
@@ -115,7 +115,7 @@ class ParameterBase(BaseModel):
     - for `cookie` - `form`.
     """
 
-    explode: bool = False
+    explode: Optional[bool] = None
     """
     When this is true, parameter values of type `array` or `object` generate separate 
     parameters for each value of the array or key-value pair of the map.