diff --git a/fluentd/fluent-plugin-grafana-loki/lib/fluent/plugin/out_loki.rb b/fluentd/fluent-plugin-grafana-loki/lib/fluent/plugin/out_loki.rb
index 1a7c2fb592274..c02426684a6c1 100644
--- a/fluentd/fluent-plugin-grafana-loki/lib/fluent/plugin/out_loki.rb
+++ b/fluentd/fluent-plugin-grafana-loki/lib/fluent/plugin/out_loki.rb
@@ -135,10 +135,8 @@ def labels_to_protocol(data_labels)
         data_labels = {} if data_labels.nil?
         data_labels = data_labels.merge(@extra_labels)
 
-        unless data_labels.nil?
-          data_labels.each do |k, v|
-            formatted_labels.push("#{k}=\"#{v}\"")
-          end
+        data_labels.each do |k, v|
+          formatted_labels.push("#{k}=\"#{v.gsub('"','\\"')}\"") if v
         end
         '{' + formatted_labels.join(',') + '}'
       end