diff --git a/core/ResponseDefinitions.php b/core/ResponseDefinitions.php
index 82421a58039e5..6f3380bab259a 100644
--- a/core/ResponseDefinitions.php
+++ b/core/ResponseDefinitions.php
@@ -212,6 +212,7 @@
  *     endedAt: ?int,
  *     allowCleanup: bool,
  *     includeWatermark: bool,
+ *     userFacingErrorMessage: ?string,
  * }
  *
  * @psalm-type CoreProfileAction = array{
diff --git a/core/openapi-ex_app.json b/core/openapi-ex_app.json
index f2dcf97cf34c0..5fbc10f465bee 100644
--- a/core/openapi-ex_app.json
+++ b/core/openapi-ex_app.json
@@ -203,7 +203,8 @@
                     "startedAt",
                     "endedAt",
                     "allowCleanup",
-                    "includeWatermark"
+                    "includeWatermark",
+                    "userFacingErrorMessage"
                 ],
                 "properties": {
                     "id": {
@@ -280,6 +281,10 @@
                     },
                     "includeWatermark": {
                         "type": "boolean"
+                    },
+                    "userFacingErrorMessage": {
+                        "type": "string",
+                        "nullable": true
                     }
                 }
             },
diff --git a/core/openapi-full.json b/core/openapi-full.json
index b5bf508a701c8..ae829249c31fc 100644
--- a/core/openapi-full.json
+++ b/core/openapi-full.json
@@ -663,7 +663,8 @@
                     "startedAt",
                     "endedAt",
                     "allowCleanup",
-                    "includeWatermark"
+                    "includeWatermark",
+                    "userFacingErrorMessage"
                 ],
                 "properties": {
                     "id": {
@@ -740,6 +741,10 @@
                     },
                     "includeWatermark": {
                         "type": "boolean"
+                    },
+                    "userFacingErrorMessage": {
+                        "type": "string",
+                        "nullable": true
                     }
                 }
             },
diff --git a/core/openapi.json b/core/openapi.json
index 19c0d9eb43b61..9c03e43bcfdcc 100644
--- a/core/openapi.json
+++ b/core/openapi.json
@@ -663,7 +663,8 @@
                     "startedAt",
                     "endedAt",
                     "allowCleanup",
-                    "includeWatermark"
+                    "includeWatermark",
+                    "userFacingErrorMessage"
                 ],
                 "properties": {
                     "id": {
@@ -740,6 +741,10 @@
                     },
                     "includeWatermark": {
                         "type": "boolean"
+                    },
+                    "userFacingErrorMessage": {
+                        "type": "string",
+                        "nullable": true
                     }
                 }
             },
diff --git a/lib/public/TaskProcessing/Task.php b/lib/public/TaskProcessing/Task.php
index a2899a1f1c977..f0096c42a7038 100644
--- a/lib/public/TaskProcessing/Task.php
+++ b/lib/public/TaskProcessing/Task.php
@@ -295,7 +295,7 @@ final public function setIncludeWatermark(bool $includeWatermark): void {
 	}
 
 	/**
-	 * @psalm-return array{id: int, lastUpdated: int, type: string, status: 'STATUS_CANCELLED'|'STATUS_FAILED'|'STATUS_SUCCESSFUL'|'STATUS_RUNNING'|'STATUS_SCHEDULED'|'STATUS_UNKNOWN', userId: ?string, appId: string, input: array<string, list<numeric|string>|numeric|string>, output: ?array<string, list<numeric|string>|numeric|string>, customId: ?string, completionExpectedAt: ?int, progress: ?float, scheduledAt: ?int, startedAt: ?int, endedAt: ?int, allowCleanup: bool, includeWatermark: bool}
+	 * @psalm-return array{id: int, lastUpdated: int, type: string, status: 'STATUS_CANCELLED'|'STATUS_FAILED'|'STATUS_SUCCESSFUL'|'STATUS_RUNNING'|'STATUS_SCHEDULED'|'STATUS_UNKNOWN', userId: ?string, appId: string, input: array<string, list<numeric|string>|numeric|string>, output: ?array<string, list<numeric|string>|numeric|string>, customId: ?string, completionExpectedAt: ?int, progress: ?float, scheduledAt: ?int, startedAt: ?int, endedAt: ?int, allowCleanup: bool, includeWatermark: bool, userFacingErrorMessage: ?string}
 	 * @since 30.0.0
 	 */
 	final public function jsonSerialize(): array {
@@ -316,6 +316,7 @@ final public function jsonSerialize(): array {
 			'endedAt' => $this->getEndedAt(),
 			'allowCleanup' => $this->getAllowCleanup(),
 			'includeWatermark' => $this->getIncludeWatermark(),
+			'userFacingErrorMessage' => $this->getUserFacingErrorMessage(),
 		];
 	}
 
diff --git a/openapi.json b/openapi.json
index 5549bebf1f735..fc220c51fb415 100644
--- a/openapi.json
+++ b/openapi.json
@@ -709,7 +709,8 @@
                     "startedAt",
                     "endedAt",
                     "allowCleanup",
-                    "includeWatermark"
+                    "includeWatermark",
+                    "userFacingErrorMessage"
                 ],
                 "properties": {
                     "id": {
@@ -786,6 +787,10 @@
                     },
                     "includeWatermark": {
                         "type": "boolean"
+                    },
+                    "userFacingErrorMessage": {
+                        "type": "string",
+                        "nullable": true
                     }
                 }
             },