diff --git a/api_names_out.yaml b/api_names_out.yaml
index a0423db1883..80fe1370645 100644
--- a/api_names_out.yaml
+++ b/api_names_out.yaml
@@ -155115,6 +155115,7 @@
 "/dataflow:v1b3/RuntimeMetadata/parameters/parameter": parameter
 "/dataflow:v1b3/RuntimeMetadata/sdkInfo": sdk_info
 "/dataflow:v1b3/RuntimeUpdatableParams": runtime_updatable_params
+"/dataflow:v1b3/RuntimeUpdatableParams/acceptableBacklogDuration": acceptable_backlog_duration
 "/dataflow:v1b3/RuntimeUpdatableParams/maxNumWorkers": max_num_workers
 "/dataflow:v1b3/RuntimeUpdatableParams/minNumWorkers": min_num_workers
 "/dataflow:v1b3/RuntimeUpdatableParams/workerUtilizationHint": worker_utilization_hint
diff --git a/generated/google-apis-dataflow_v1b3/CHANGELOG.md b/generated/google-apis-dataflow_v1b3/CHANGELOG.md
index b4f92a2e83d..567b1421404 100644
--- a/generated/google-apis-dataflow_v1b3/CHANGELOG.md
+++ b/generated/google-apis-dataflow_v1b3/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Release history for google-apis-dataflow_v1b3
 
+### v0.74.0 (2025-12-21)
+
+* Regenerated from discovery document revision 20251214
+
 ### v0.73.0 (2025-10-12)
 
 * Regenerated from discovery document revision 20251003
diff --git a/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/classes.rb b/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/classes.rb
index d1008e05505..a9f410e7448 100644
--- a/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/classes.rb
+++ b/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/classes.rb
@@ -4837,6 +4837,12 @@ def update!(**args)
       class RuntimeUpdatableParams
         include Google::Apis::Core::Hashable
       
+        # Optional. The backlog threshold duration in seconds for autoscaling. Value
+        # must be non-negative.
+        # Corresponds to the JSON property `acceptableBacklogDuration`
+        # @return [String]
+        attr_accessor :acceptable_backlog_duration
+      
         # The maximum number of workers to cap autoscaling at. This field is currently
         # only supported for Streaming Engine jobs.
         # Corresponds to the JSON property `maxNumWorkers`
@@ -4864,6 +4870,7 @@ def initialize(**args)
       
         # Update properties of this object
         def update!(**args)
+          @acceptable_backlog_duration = args[:acceptable_backlog_duration] if args.key?(:acceptable_backlog_duration)
           @max_num_workers = args[:max_num_workers] if args.key?(:max_num_workers)
           @min_num_workers = args[:min_num_workers] if args.key?(:min_num_workers)
           @worker_utilization_hint = args[:worker_utilization_hint] if args.key?(:worker_utilization_hint)
diff --git a/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/gem_version.rb b/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/gem_version.rb
index 6b2a512c49d..a8f45c10b3c 100644
--- a/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/gem_version.rb
+++ b/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/gem_version.rb
@@ -16,13 +16,13 @@ module Google
   module Apis
     module DataflowV1b3
       # Version of the google-apis-dataflow_v1b3 gem
-      GEM_VERSION = "0.73.0"
+      GEM_VERSION = "0.74.0"
 
       # Version of the code generator used to generate this client
       GENERATOR_VERSION = "0.18.0"
 
       # Revision of the discovery document this client was generated from
-      REVISION = "20251003"
+      REVISION = "20251214"
     end
   end
 end
diff --git a/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/representations.rb b/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/representations.rb
index f9ceb0f72c0..ae60a23be0f 100644
--- a/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/representations.rb
+++ b/generated/google-apis-dataflow_v1b3/lib/google/apis/dataflow_v1b3/representations.rb
@@ -2479,6 +2479,7 @@ class Representation < Google::Apis::Core::JsonRepresentation
       class RuntimeUpdatableParams
         # @private
         class Representation < Google::Apis::Core::JsonRepresentation
+          property :acceptable_backlog_duration, as: 'acceptableBacklogDuration'
           property :max_num_workers, as: 'maxNumWorkers'
           property :min_num_workers, as: 'minNumWorkers'
           property :worker_utilization_hint, as: 'workerUtilizationHint'