diff --git a/readthedocs/builds/migrations/0038_track_task_id.py b/readthedocs/builds/migrations/0041_track_task_id.py
similarity index 88%
rename from readthedocs/builds/migrations/0038_track_task_id.py
rename to readthedocs/builds/migrations/0041_track_task_id.py
index 411b656dc89..e7bcd23143c 100644
--- a/readthedocs/builds/migrations/0038_track_task_id.py
+++ b/readthedocs/builds/migrations/0041_track_task_id.py
@@ -6,7 +6,7 @@
 class Migration(migrations.Migration):
 
     dependencies = [
-        ('builds', '0037_alter_build_cold_storage'),
+        ('builds', '0040_remove_old_jsonfields'),
     ]
 
     operations = [
diff --git a/readthedocs/builds/views.py b/readthedocs/builds/views.py
index 50a826ed89b..69d6b9407f0 100644
--- a/readthedocs/builds/views.py
+++ b/readthedocs/builds/views.py
@@ -16,17 +16,14 @@
 from django.views.generic import DetailView, ListView
 from requests.utils import quote
 
+from readthedocs.builds.constants import BUILD_STATE_TRIGGERED, BUILD_STATE_FINISHED
 from readthedocs.builds.filters import BuildListFilter
 from readthedocs.builds.models import Build, Version
 from readthedocs.core.permissions import AdminPermission
 from readthedocs.core.utils import trigger_build
-from readthedocs.doc_builder.exceptions import BuildAppError
+from readthedocs.doc_builder.exceptions import BuildAppError, BuildCancelled
 from readthedocs.projects.models import Project
-
-try:
-    from readthedocsinc.worker import app
-except ImportError:
-    from readthedocs.worker import app
+from readthedocs.worker import app
 
 
 log = structlog.get_logger(__name__)
@@ -165,8 +162,23 @@ def post(self, request, project_slug, build_pk):
             return HttpResponseForbidden()
 
         # NOTE: `terminate=True` is required for the child to attend our call
-        # immediately. Otherwise, it finishes the task.
-        app.control.revoke(build.task_id, signal=signal.SIGINT, terminate=True)
+        # immediately when it's running the build. Otherwise, it finishes the
+        # task. However, to revoke a task that has not started yet, we don't
+        # need it.
+        if build.state == BUILD_STATE_TRIGGERED:
+            # Since the task won't be executed at all, we need to update the
+            # Build object here.
+            terminate = False
+            build.state = BUILD_STATE_FINISHED
+            build.success = False
+            build.error = BuildCancelled.message
+            build.save()
+        else:
+            # In this case, we left the update of the Build object to the task
+            # itself to be executed in the `on_failure` handler.
+            terminate = True
+
+        app.control.revoke(build.task_id, signal=signal.SIGINT, terminate=terminate)
 
         return HttpResponseRedirect(
             reverse('builds_detail', args=[project.slug, build.pk]),
diff --git a/readthedocs/templates/builds/build_detail.html b/readthedocs/templates/builds/build_detail.html
index c376d2f0dcd..7b6539118cc 100644
--- a/readthedocs/templates/builds/build_detail.html
+++ b/readthedocs/templates/builds/build_detail.html
@@ -30,10 +30,12 @@
 {% block content %}
   <div class="build build-detail" id="build-detail">
 
+    {% if build.state != "finished" %}
     <form method="post" action="{% url "builds_detail" build.version.project.slug build.pk %}">
       {% csrf_token %}
       <input type="submit" value="{% trans "Cancel build" %}">
     </form>
+    {% endif %}
 
     <!-- Build meta data -->
     <ul class="build-meta">