diff --git a/modules/openapi-generator/src/main/resources/python/rest.mustache b/modules/openapi-generator/src/main/resources/python/rest.mustache
index 9e733864895..21c8d5b44c0 100644
--- a/modules/openapi-generator/src/main/resources/python/rest.mustache
+++ b/modules/openapi-generator/src/main/resources/python/rest.mustache
@@ -129,15 +129,15 @@ class RESTClientObject(object):
                 timeout = urllib3.Timeout(
                     connect=_request_timeout[0], read=_request_timeout[1])
 
-        if 'Content-Type' not in headers:
-            headers['Content-Type'] = 'application/json'
-
         try:
             # For `POST`, `PUT`, `PATCH`, `OPTIONS`, `DELETE`
             if method in ['POST', 'PUT', 'PATCH', 'OPTIONS', 'DELETE']:
+                # Only set a default Content-Type for POST, PUT, PATCH and OPTIONS requests
+                if (method != 'DELETE') and ('Content-Type' not in headers):
+                    headers['Content-Type'] = 'application/json'
                 if query_params:
                     url += '?' + urlencode(query_params)
-                if re.search('json', headers['Content-Type'], re.IGNORECASE):
+                if ('Content-Type' not in headers) or (re.search('json', headers['Content-Type'], re.IGNORECASE)):
                     request_body = None
                     if body is not None:
                         request_body = json.dumps(body)
diff --git a/samples/client/petstore/python/petstore_api/rest.py b/samples/client/petstore/python/petstore_api/rest.py
index a1d580fbe05..a38fcec1c84 100644
--- a/samples/client/petstore/python/petstore_api/rest.py
+++ b/samples/client/petstore/python/petstore_api/rest.py
@@ -137,15 +137,15 @@ class RESTClientObject(object):
                 timeout = urllib3.Timeout(
                     connect=_request_timeout[0], read=_request_timeout[1])
 
-        if 'Content-Type' not in headers:
-            headers['Content-Type'] = 'application/json'
-
         try:
             # For `POST`, `PUT`, `PATCH`, `OPTIONS`, `DELETE`
             if method in ['POST', 'PUT', 'PATCH', 'OPTIONS', 'DELETE']:
+                # Only set a default Content-Type for POST, PUT, PATCH and OPTIONS requests
+                if (method != 'DELETE') and ('Content-Type' not in headers):
+                    headers['Content-Type'] = 'application/json'
                 if query_params:
                     url += '?' + urlencode(query_params)
-                if re.search('json', headers['Content-Type'], re.IGNORECASE):
+                if ('Content-Type' not in headers) or (re.search('json', headers['Content-Type'], re.IGNORECASE)):
                     request_body = None
                     if body is not None:
                         request_body = json.dumps(body)
diff --git a/samples/client/petstore/python_disallowAdditionalPropertiesIfNotPresent/petstore_api/rest.py b/samples/client/petstore/python_disallowAdditionalPropertiesIfNotPresent/petstore_api/rest.py
index a1d580fbe05..a38fcec1c84 100644
--- a/samples/client/petstore/python_disallowAdditionalPropertiesIfNotPresent/petstore_api/rest.py
+++ b/samples/client/petstore/python_disallowAdditionalPropertiesIfNotPresent/petstore_api/rest.py
@@ -137,15 +137,15 @@ class RESTClientObject(object):
                 timeout = urllib3.Timeout(
                     connect=_request_timeout[0], read=_request_timeout[1])
 
-        if 'Content-Type' not in headers:
-            headers['Content-Type'] = 'application/json'
-
         try:
             # For `POST`, `PUT`, `PATCH`, `OPTIONS`, `DELETE`
             if method in ['POST', 'PUT', 'PATCH', 'OPTIONS', 'DELETE']:
+                # Only set a default Content-Type for POST, PUT, PATCH and OPTIONS requests
+                if (method != 'DELETE') and ('Content-Type' not in headers):
+                    headers['Content-Type'] = 'application/json'
                 if query_params:
                     url += '?' + urlencode(query_params)
-                if re.search('json', headers['Content-Type'], re.IGNORECASE):
+                if ('Content-Type' not in headers) or (re.search('json', headers['Content-Type'], re.IGNORECASE)):
                     request_body = None
                     if body is not None:
                         request_body = json.dumps(body)
diff --git a/samples/openapi3/client/extensions/x-auth-id-alias/python/x_auth_id_alias/rest.py b/samples/openapi3/client/extensions/x-auth-id-alias/python/x_auth_id_alias/rest.py
index a0a26a797db..a7c5fd3304a 100644
--- a/samples/openapi3/client/extensions/x-auth-id-alias/python/x_auth_id_alias/rest.py
+++ b/samples/openapi3/client/extensions/x-auth-id-alias/python/x_auth_id_alias/rest.py
@@ -137,15 +137,15 @@ class RESTClientObject(object):
                 timeout = urllib3.Timeout(
                     connect=_request_timeout[0], read=_request_timeout[1])
 
-        if 'Content-Type' not in headers:
-            headers['Content-Type'] = 'application/json'
-
         try:
             # For `POST`, `PUT`, `PATCH`, `OPTIONS`, `DELETE`
             if method in ['POST', 'PUT', 'PATCH', 'OPTIONS', 'DELETE']:
+                # Only set a default Content-Type for POST, PUT, PATCH and OPTIONS requests
+                if (method != 'DELETE') and ('Content-Type' not in headers):
+                    headers['Content-Type'] = 'application/json'
                 if query_params:
                     url += '?' + urlencode(query_params)
-                if re.search('json', headers['Content-Type'], re.IGNORECASE):
+                if ('Content-Type' not in headers) or (re.search('json', headers['Content-Type'], re.IGNORECASE)):
                     request_body = None
                     if body is not None:
                         request_body = json.dumps(body)
diff --git a/samples/openapi3/client/features/dynamic-servers/python/dynamic_servers/rest.py b/samples/openapi3/client/features/dynamic-servers/python/dynamic_servers/rest.py
index 979c58eb200..191d850b87d 100644
--- a/samples/openapi3/client/features/dynamic-servers/python/dynamic_servers/rest.py
+++ b/samples/openapi3/client/features/dynamic-servers/python/dynamic_servers/rest.py
@@ -137,15 +137,15 @@ class RESTClientObject(object):
                 timeout = urllib3.Timeout(
                     connect=_request_timeout[0], read=_request_timeout[1])
 
-        if 'Content-Type' not in headers:
-            headers['Content-Type'] = 'application/json'
-
         try:
             # For `POST`, `PUT`, `PATCH`, `OPTIONS`, `DELETE`
             if method in ['POST', 'PUT', 'PATCH', 'OPTIONS', 'DELETE']:
+                # Only set a default Content-Type for POST, PUT, PATCH and OPTIONS requests
+                if (method != 'DELETE') and ('Content-Type' not in headers):
+                    headers['Content-Type'] = 'application/json'
                 if query_params:
                     url += '?' + urlencode(query_params)
-                if re.search('json', headers['Content-Type'], re.IGNORECASE):
+                if ('Content-Type' not in headers) or (re.search('json', headers['Content-Type'], re.IGNORECASE)):
                     request_body = None
                     if body is not None:
                         request_body = json.dumps(body)
diff --git a/samples/openapi3/client/petstore/python/petstore_api/rest.py b/samples/openapi3/client/petstore/python/petstore_api/rest.py
index a1d580fbe05..a38fcec1c84 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/rest.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/rest.py
@@ -137,15 +137,15 @@ class RESTClientObject(object):
                 timeout = urllib3.Timeout(
                     connect=_request_timeout[0], read=_request_timeout[1])
 
-        if 'Content-Type' not in headers:
-            headers['Content-Type'] = 'application/json'
-
         try:
             # For `POST`, `PUT`, `PATCH`, `OPTIONS`, `DELETE`
             if method in ['POST', 'PUT', 'PATCH', 'OPTIONS', 'DELETE']:
+                # Only set a default Content-Type for POST, PUT, PATCH and OPTIONS requests
+                if (method != 'DELETE') and ('Content-Type' not in headers):
+                    headers['Content-Type'] = 'application/json'
                 if query_params:
                     url += '?' + urlencode(query_params)
-                if re.search('json', headers['Content-Type'], re.IGNORECASE):
+                if ('Content-Type' not in headers) or (re.search('json', headers['Content-Type'], re.IGNORECASE)):
                     request_body = None
                     if body is not None:
                         request_body = json.dumps(body)