diff --git a/infra/run-domain-check.sh b/infra/run-domain-check.sh
index 7b3ce31..a701b21 100755
--- a/infra/run-domain-check.sh
+++ b/infra/run-domain-check.sh
@@ -87,8 +87,9 @@ try:
 except Exception:
     d={}
 rid=os.environ['REG_ID']
+# Flowable's task-query returns the included process variables under 'variables'.
 print(next((t['id'] for t in (d.get('data') or [])
-    if any(v.get('name')=='registrationId' and v.get('value')==rid for v in (t.get('processVariables') or []))), ''))"; }
+    if any(v.get('name')=='registrationId' and v.get('value')==rid for v in (t.get('variables') or []))), ''))"; }
 
 flcurl() { docker run --rm --network "$net" curlimages/curl:latest -fsS -u rest-admin:test "$@"; }
 query='{"processDefinitionKey":"registratie","taskDefinitionKey":"Beoordelen","includeProcessVariables":true}'
diff --git a/services/domain/Big.Infrastructure/FlowableWorkflowClient.cs b/services/domain/Big.Infrastructure/FlowableWorkflowClient.cs
index 597a6e6..f782cea 100644
--- a/services/domain/Big.Infrastructure/FlowableWorkflowClient.cs
+++ b/services/domain/Big.Infrastructure/FlowableWorkflowClient.cs
@@ -137,11 +137,13 @@ public sealed class FlowableWorkflowClient(HttpClient http, FlowableOptions opti
 
     private sealed record UserTaskDto(
         [property: JsonPropertyName("id")] string Id,
-        [property: JsonPropertyName("processVariables")] IReadOnlyList<Variable>? ProcessVariables)
+        // Flowable's task-query returns the (included) process variables under "variables", not
+        // "processVariables"; the request opts in via includeProcessVariables.
+        [property: JsonPropertyName("variables")] IReadOnlyList<Variable>? Variables)
     {
         /// <summary>The registration id this task carries as a process variable.</summary>
         public string RegistrationId() =>
-            ProcessVariables?.SingleOrDefault(v => v.Name == "registrationId")?.Value
+            Variables?.SingleOrDefault(v => v.Name == "registrationId")?.Value
             ?? throw new InvalidOperationException($"Beoordelen task {Id} carries no registrationId variable.");
     }
 
diff --git a/services/domain/Big.Tests/FlowableWorkflowClientTests.cs b/services/domain/Big.Tests/FlowableWorkflowClientTests.cs
index 3262506..f1bf579 100644
--- a/services/domain/Big.Tests/FlowableWorkflowClientTests.cs
+++ b/services/domain/Big.Tests/FlowableWorkflowClientTests.cs
@@ -158,7 +158,7 @@ public class FlowableWorkflowClientTests
         var capture = new RequestCapture();
         var client = Client(capture.Responds(HttpStatusCode.OK,
             $$"""
-            {"data":[{"id":"task-1","processVariables":[{"name":"registrationId","type":"string","value":"{{rid}}"}]}],"total":1}
+            {"data":[{"id":"task-1","variables":[{"name":"registrationId","type":"string","value":"{{rid}}"}]}],"total":1}
             """));
 
         var tasks = await client.GetOpenBeoordelingenAsync();
@@ -192,7 +192,7 @@ public class FlowableWorkflowClientTests
     {
         var capture = new RequestCapture();
         var client = Client(capture.Responds(HttpStatusCode.OK,
-            """{"data":[{"id":"task-1","processVariables":[]}],"total":1}"""));
+            """{"data":[{"id":"task-1","variables":[]}],"total":1}"""));
 
         var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => client.GetOpenBeoordelingenAsync());
         Assert.Contains("task-1", ex.Message);