diff --git a/java/src/main/java/monasca/persister/repository/influxdb/InfluxV9MetricRepo.java b/java/src/main/java/monasca/persister/repository/influxdb/InfluxV9MetricRepo.java
index 2435306b..9aeb16b4 100644
--- a/java/src/main/java/monasca/persister/repository/influxdb/InfluxV9MetricRepo.java
+++ b/java/src/main/java/monasca/persister/repository/influxdb/InfluxV9MetricRepo.java
@@ -95,9 +95,9 @@ public class InfluxV9MetricRepo extends InfluxMetricRepo {
 
     String valueMetaJSONString = measurement.getValueMetaJSONString();
 
-    if (valueMetaJSONString == null) {
+    if (valueMetaJSONString == null || valueMetaJSONString.isEmpty()) {
 
-      valueMap.put("value_meta", "");
+      valueMap.put("value_meta", "{}");
 
     } else {
 
diff --git a/monasca_persister/persister.py b/monasca_persister/persister.py
index c1aecd54..2dd23305 100644
--- a/monasca_persister/persister.py
+++ b/monasca_persister/persister.py
@@ -517,7 +517,7 @@ class MetricPersister(AbstractPersister):
 
         else:
 
-            value_meta = ''
+            value_meta = {}
 
         LOG.debug('value_meta: %s', value_meta)
 
@@ -533,8 +533,7 @@ class MetricPersister(AbstractPersister):
                 "fields": {
                     "value": value,
                     "value_meta": json.dumps(value_meta,
-                                             ensure_ascii=False).encode(
-                        'utf8') if value_meta else value_meta.encode('utf8')
+                                             ensure_ascii=False).encode('utf8')
                 },
                 "tags": tags}