diff --git a/foca/api/register_openapi.py b/foca/api/register_openapi.py
index 8881005..320f76e 100644
--- a/foca/api/register_openapi.py
+++ b/foca/api/register_openapi.py
@@ -12,6 +12,12 @@
 # Get logger instance
 logger = logging.getLogger(__name__)
 
+# Path Item object fields which contain an Operation object (ie: HTTP verbs).
+# Reference: https://swagger.io/specification/v3/#path-item-object
+_OPERATION_OBJECT_FIELDS = frozenset({
+    "get", "put", "post", "delete", "options", "head", "patch", "trace",
+})
+
 
 def register_openapi(
         app: App,
@@ -51,7 +57,9 @@ def register_openapi(
         if spec.add_operation_fields is not None:
             for key, val in spec.add_operation_fields.items():
                 for path_item_object in spec_parsed.get('paths', {}).values():
-                    for operation_object in path_item_object.values():
+                    for operation, operation_object in path_item_object.items():
+                        if operation not in _OPERATION_OBJECT_FIELDS:
+                            continue
                         operation_object[key] = val
             logger.debug(
                 f"Added operation fields: {spec.add_operation_fields}"
diff --git a/tests/api/test_register_openapi.py b/tests/api/test_register_openapi.py
index 546f425..cc8a7d4 100644
--- a/tests/api/test_register_openapi.py
+++ b/tests/api/test_register_openapi.py
@@ -21,6 +21,8 @@
 PATH_SPECS_2_YAML_ADDITION = DIR / "openapi_2_petstore.addition.yaml"
 PATH_SPECS_3_YAML_ORIGINAL = DIR / "openapi_3_petstore.original.yaml"
 PATH_SPECS_3_YAML_MODIFIED = DIR / "openapi_3_petstore.modified.yaml"
+PATH_SPECS_3_PATHITEMPARAM_YAML_ORIGINAL = DIR / "openapi_3_petstore_pathitemparam.original.yaml"
+PATH_SPECS_3_PATHITEMPARAM_YAML_MODIFIED = DIR / "openapi_3_petstore_pathitemparam.modified.yaml"
 PATH_SPECS_INVALID_JSON = DIR / "invalid.json"
 PATH_SPECS_INVALID_YAML = DIR / "invalid.openapi.yaml"
 PATH_NOT_FOUND = DIR / "does/not/exist.yaml"
@@ -64,6 +66,15 @@
     "disable_auth": False,
     "connexion": CONNEXION_CONFIG,
 }
+SPEC_CONFIG_3_PATHITEMPARAM = {
+    "path": PATH_SPECS_3_PATHITEMPARAM_YAML_ORIGINAL,
+    "path_out": PATH_SPECS_3_PATHITEMPARAM_YAML_MODIFIED,
+    "append": [APPEND],
+    "add_operation_fields": OPERATION_FIELDS_3,
+    "add_security_fields": SECURITY_FIELDS_3,
+    "disable_auth": False,
+    "connexion": CONNEXION_CONFIG,
+}
 SPEC_CONFIG_2_JSON = deepcopy(SPEC_CONFIG_2)
 SPEC_CONFIG_2_JSON['path'] = PATH_SPECS_2_JSON_ORIGINAL
 SPEC_CONFIG_2_LIST = deepcopy(SPEC_CONFIG_2)
@@ -92,6 +103,16 @@ def test_openapi_3_yaml(self):
         res = register_openapi(app=app, specs=spec_configs)
         assert isinstance(res, App)
 
+    def test_openapi_3_pathitemparam_yaml(self):
+        """
+        Successfully register OpenAPI 3 YAML specs with PathItem.parameters
+        field with Connexion app.
+        """
+        app = App(__name__)
+        spec_configs = [SpecConfig(**SPEC_CONFIG_3_PATHITEMPARAM)]
+        res = register_openapi(app=app, specs=spec_configs)
+        assert isinstance(res, App)
+
     def test_openapi_2_json(self):
         """Successfully register OpenAPI 2 JSON specs with Connexion app."""
         app = App(__name__)
diff --git a/tests/test_files/openapi_3_petstore_pathitemparam.modified.yaml b/tests/test_files/openapi_3_petstore_pathitemparam.modified.yaml
new file mode 100644
index 0000000..41f1afa
--- /dev/null
+++ b/tests/test_files/openapi_3_petstore_pathitemparam.modified.yaml
@@ -0,0 +1,114 @@
+components:
+  schemas:
+    Error:
+      properties:
+        code:
+          format: int32
+          type: integer
+        message:
+          type: string
+      required:
+      - code
+      - message
+      type: object
+    Pet:
+      properties:
+        id:
+          format: int64
+          type: integer
+        name:
+          type: string
+        tag:
+          type: string
+      required:
+      - id
+      - name
+      type: object
+    Pets:
+      items:
+        $ref: '#/components/schemas/Pet'
+      type: array
+info:
+  license:
+    name: MIT
+  title: Swagger Petstore
+  version: 1.0.0
+openapi: 3.0.0
+paths:
+  /pets:
+    get:
+      operationId: listPets
+      parameters:
+      - description: How many items to return at one time (max 100)
+        in: query
+        name: limit
+        required: false
+        schema:
+          format: int32
+          type: integer
+      responses:
+        '200':
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Pets'
+          description: A paged array of pets
+          headers:
+            x-next:
+              description: A link to the next page of responses
+              schema:
+                type: string
+        default:
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
+          description: unexpected error
+      summary: List all pets
+      tags:
+      - pets
+      x-openapi-router-controller: controllers
+    post:
+      operationId: createPets
+      responses:
+        '201':
+          description: Null response
+        default:
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
+          description: unexpected error
+      summary: Create a pet
+      tags:
+      - pets
+      x-openapi-router-controller: controllers
+  /pets/{petId}:
+    parameters:
+    - description: The id of the pet to retrieve
+      in: path
+      name: petId
+      required: true
+      schema:
+        type: string
+    get:
+      operationId: showPetById
+      responses:
+        '200':
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Pet'
+          description: Expected response to a valid request
+        default:
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
+          description: unexpected error
+      summary: Info for a specific pet
+      tags:
+      - pets
+      x-openapi-router-controller: controllers
+servers:
+- url: http://petstore.swagger.io/v2
diff --git a/tests/test_files/openapi_3_petstore_pathitemparam.original.yaml b/tests/test_files/openapi_3_petstore_pathitemparam.original.yaml
new file mode 100644
index 0000000..f301de5
--- /dev/null
+++ b/tests/test_files/openapi_3_petstore_pathitemparam.original.yaml
@@ -0,0 +1,122 @@
+openapi: "3.0.0"
+info:
+  version: 1.0.0
+  title: Swagger Petstore
+  license:
+    name: MIT
+servers:
+  - url: http://petstore.swagger.io/v2
+security:
+  - bearerAuth: []
+paths:
+  /pets:
+    get:
+      summary: List all pets
+      operationId: listPets
+      tags:
+        - pets
+      parameters:
+        - name: limit
+          in: query
+          description: How many items to return at one time (max 100)
+          required: false
+          schema:
+            type: integer
+            format: int32
+      responses:
+        '200':
+          description: A paged array of pets
+          headers:
+            x-next:
+              description: A link to the next page of responses
+              schema:
+                type: string
+          content:
+            application/json:    
+              schema:
+                $ref: "#/components/schemas/Pets"
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+      security:
+        - bearerAuth: []
+    post:
+      summary: Create a pet
+      operationId: createPets
+      tags:
+        - pets
+      responses:
+        '201':
+          description: Null response
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+      security:
+        - bearerAuth: []
+  /pets/{petId}:
+    parameters:
+      - name: petId
+        in: path
+        required: true
+        description: The id of the pet to retrieve
+        schema:
+          type: string
+    get:
+      summary: Info for a specific pet
+      operationId: showPetById
+      tags:
+        - pets
+      responses:
+        '200':
+          description: Expected response to a valid request
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pet"
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+components:
+  securitySchemes:
+    bearerAuth:
+      type: http
+      scheme: bearer
+      bearerFormat: JWT
+  schemas:
+    Pet:
+      type: object
+      required:
+        - id
+        - name
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string
+    Pets:
+      type: array
+      items:
+        $ref: "#/components/schemas/Pet"
+    Error:
+      type: object
+      required:
+        - code
+        - message
+      properties:
+        code:
+          type: integer
+          format: int32
+        message:
+          type: string