1 files changed, 17 insertions, 13 deletions
diff --git a/app/controllers/projects/jobs_controller.rb b/app/controllers/projects/jobs_controller.rb
index 900ebc61856..d2703f5cc38 100644
--- a/app/controllers/projects/jobs_controller.rb
+++ b/app/controllers/projects/jobs_controller.rb
@@ -49,21 +49,25 @@ class Projects::JobsController < Projects::ApplicationController
   # rubocop: enable CodeReuse/ActiveRecord
 
   def trace
-    @build.trace.read do |stream|
-      respond_to do |format|
-        format.json do
-          @build.trace.being_watched!
-
-          build_trace = Ci::BuildTrace.new(
-            build: @build,
-            stream: stream,
-            state: params[:state])
-
-          render json: BuildTraceSerializer
-            .new(project: @project, current_user: @current_user)
-            .represent(build_trace)
+    @build.trace.being_watched! if @build.running?
+
+    if @build.has_trace?
+      @build.trace.read do |stream|
+        respond_to do |format|
+          format.json do
+            build_trace = Ci::BuildTrace.new(
+              build: @build,
+              stream: stream,
+              state: params[:state])
+
+            render json: BuildTraceSerializer
+              .new(project: @project, current_user: @current_user)
+              .represent(build_trace)
+          end
         end
       end
+    else
+      head :no_content
     end
   end