diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1340b161b..56df818b5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,11 @@ Changes are grouped as follows
 - `Fixed` for any bug fixes.
 - `Security` in case of vulnerabilities.
 
+## [7.55.3] - 2024-08-29
+### Fixed
+- [Feature Preview - alpha] data workflows: `workflowExecutionId` in `cognite.client.data_classes.workflows.WorkflowTriggerRun`
+ can be null or missing, as according to the API spec.
+
 ## [7.55.2] - 2024-08-29
 ### Fixed
 - Turn workflow_orchestration into data_workflows and add trigger doc, fix attribute names in data classes
diff --git a/cognite/client/_version.py b/cognite/client/_version.py
index a2f3828ca..91c5894fd 100644
--- a/cognite/client/_version.py
+++ b/cognite/client/_version.py
@@ -1,4 +1,4 @@
 from __future__ import annotations
 
-__version__ = "7.55.2"
+__version__ = "7.55.3"
 __api_subversion__ = "20230101"
diff --git a/cognite/client/data_classes/workflows.py b/cognite/client/data_classes/workflows.py
index 26f13eb6e..2e0f41d87 100644
--- a/cognite/client/data_classes/workflows.py
+++ b/cognite/client/data_classes/workflows.py
@@ -1385,8 +1385,8 @@ def __init__(
         fire_time: int,
         workflow_external_id: str,
         workflow_version: str,
-        workflow_execution_id: str,
         status: Literal["success", "failed"],
+        workflow_execution_id: str | None = None,
         reason_for_failure: str | None = None,
     ) -> None:
         self.external_id = external_id
@@ -1403,9 +1403,10 @@ def dump(self, camel_case: bool = True) -> dict[str, Any]:
             "fire_time": self.fire_time,
             "workflow_external_id": self.workflow_external_id,
             "workflow_version": self.workflow_version,
-            "workflow_execution_id": self.workflow_execution_id,
             "status": self.status,
         }
+        if self.workflow_execution_id:
+            item["workflow_execution_id"] = self.workflow_execution_id
         if self.reason_for_failure:
             item["reason_for_failure"] = self.reason_for_failure
         if camel_case:
@@ -1419,8 +1420,8 @@ def _load(cls, resource: dict, cognite_client: CogniteClient | None = None) -> W
             fire_time=resource["fireTime"],
             workflow_external_id=resource["workflowExternalId"],
             workflow_version=resource["workflowVersion"],
-            workflow_execution_id=resource["workflowExecutionId"],
             status=resource["status"],
+            workflow_execution_id=resource.get("workflowExecutionId"),
             reason_for_failure=resource.get("reasonForFailure"),
         )
 
diff --git a/pyproject.toml b/pyproject.toml
index f2c757338..0362498f3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [tool.poetry]
 name = "cognite-sdk"
 
-version = "7.55.2"
+version = "7.55.3"
 description = "Cognite Python SDK"
 readme = "README.md"
 documentation = "https://cognite-sdk-python.readthedocs-hosted.com"