diff --git a/app/models/project_services/slack_slash_commands_service.rb b/app/models/project_services/slack_slash_commands_service.rb
index cb19ebf4cadc1fdd109b2aee089eae2cd251500e..5a7cc0fb329799c90d25c92f6551f2b61cf7aa91 100644
--- a/app/models/project_services/slack_slash_commands_service.rb
+++ b/app/models/project_services/slack_slash_commands_service.rb
@@ -16,7 +16,7 @@ class SlackSlashCommandsService < ChatSlashCommandsService
   def trigger(params)
     # Format messages to be Slack-compatible
     super.tap do |result|
-      result[:text] = format(result[:text])
+      result[:text] = format(result[:text]) if result.is_a?(Hash)
     end
   end
 
diff --git a/spec/models/project_services/slack_slash_commands_service.rb b/spec/models/project_services/slack_slash_commands_service_spec.rb
similarity index 93%
rename from spec/models/project_services/slack_slash_commands_service.rb
rename to spec/models/project_services/slack_slash_commands_service_spec.rb
index 5775e4399068fc22401e95d147954283f1c98a28..5766aa340e26cfba6fcf67dfcc82a61726b684ee 100644
--- a/spec/models/project_services/slack_slash_commands_service.rb
+++ b/spec/models/project_services/slack_slash_commands_service_spec.rb
@@ -18,7 +18,8 @@ describe SlackSlashCommandsService, :models do
 
       let(:service) do
         project.create_slack_slash_commands_service(
-          properties: { token: 'token' }
+          properties: { token: 'token' },
+          active: true
         )
       end