diff --git a/lib/ci/gitlab_ci_yaml_processor.rb b/lib/ci/gitlab_ci_yaml_processor.rb
index 7f54f5f0722..e7fb1b79b7c 100644
--- a/lib/ci/gitlab_ci_yaml_processor.rb
+++ b/lib/ci/gitlab_ci_yaml_processor.rb
@@ -10,7 +10,7 @@ module Ci
     attr_reader :before_script, :image, :services, :variables, :path, :cache
 
     def initialize(config, path = nil)
-      @config = YAML.safe_load(config)
+      @config = YAML.safe_load(config, [Symbol])
       @path = path
 
       unless @config.is_a? Hash
@@ -250,4 +250,4 @@ module Ci
       end
     end
   end
-end
\ No newline at end of file
+end