diff --git a/lib/temporal.rb b/lib/temporal.rb
index 7c9060de..918860b5 100644
--- a/lib/temporal.rb
+++ b/lib/temporal.rb
@@ -90,6 +90,18 @@ def reset_workflow(namespace, workflow_id, run_id, workflow_task_id: nil, reason
       response.run_id
     end
 
+    def terminate_workflow(workflow_id, namespace: nil, run_id: nil, reason: nil, details: nil)
+      namespace ||= Temporal.configuration.namespace
+
+      client.terminate_workflow_execution(
+        namespace: namespace,
+        workflow_id: workflow_id,
+        run_id: run_id,
+        reason: reason,
+        details: details
+      )
+    end
+
     def fetch_workflow_execution_info(namespace, workflow_id, run_id)
       response = client.describe_workflow_execution(
         namespace: namespace,
diff --git a/lib/temporal/client/grpc_client.rb b/lib/temporal/client/grpc_client.rb
index eab4f1a3..5e536a54 100644
--- a/lib/temporal/client/grpc_client.rb
+++ b/lib/temporal/client/grpc_client.rb
@@ -273,7 +273,6 @@ def reset_workflow_execution(namespace:, workflow_id:, run_id:, reason:, workflo
           workflow_execution: Temporal::Api::Common::V1::WorkflowExecution.new(
             workflow_id: workflow_id,
             run_id: run_id,
-            request_id: SecureRandom.uuid
           ),
           reason: reason,
           workflow_task_finish_event_id: workflow_task_event_id
@@ -281,8 +280,25 @@ def reset_workflow_execution(namespace:, workflow_id:, run_id:, reason:, workflo
         client.reset_workflow_execution(request)
       end
 
-      def terminate_workflow_execution
-        raise NotImplementedError
+      def terminate_workflow_execution(
+        namespace:,
+        workflow_id:,
+        run_id:,
+        reason: nil,
+        details: nil
+      )
+        request = Temporal::Api::WorkflowService::V1::TerminateWorkflowExecutionRequest.new(
+          identity: identity,
+          namespace: namespace,
+          workflow_execution: Temporal::Api::Common::V1::WorkflowExecution.new(
+            workflow_id: workflow_id,
+            run_id: run_id,
+          ),
+          reason: reason,
+          details: Serializer::Payload.new(details).to_proto
+        )
+
+        client.terminate_workflow_execution(request)
       end
 
       def list_open_workflow_executions
diff --git a/spec/unit/lib/temporal_spec.rb b/spec/unit/lib/temporal_spec.rb
index dec43f7b..eecc2331 100644
--- a/spec/unit/lib/temporal_spec.rb
+++ b/spec/unit/lib/temporal_spec.rb
@@ -160,6 +160,28 @@ class TestStartWorkflow < Temporal::Workflow
       end
     end
 
+    describe '.terminate_workflow' do
+      let(:temporal_response) do
+        Temporal::Api::WorkflowService::V1::TerminateWorkflowExecutionResponse.new
+      end
+
+      before { allow(client).to receive(:terminate_workflow_execution).and_return(temporal_response) }
+
+      it 'terminates a workflow' do
+        described_class.terminate_workflow('my-workflow', reason: 'just stop it')
+
+        expect(client)
+          .to have_received(:terminate_workflow_execution)
+          .with(
+            namespace: 'default-namespace',
+            workflow_id: 'my-workflow',
+            reason: 'just stop it',
+            details: nil,
+            run_id: nil
+          )
+      end
+    end
+
     describe '.schedule_workflow' do
       let(:temporal_response) do
         Temporal::Api::WorkflowService::V1::StartWorkflowExecutionResponse.new(run_id: 'xxx')
@@ -239,7 +261,7 @@ class TestStartWorkflow < Temporal::Workflow
 
       before { allow(client).to receive(:reset_workflow_execution).and_return(temporal_response) }
 
-      context 'when decision_task_id is provided' do
+      context 'when workflow_task_id is provided' do
         let(:workflow_task_id) { 42 }
 
         it 'calls client reset_workflow_execution' do