diff --git a/plugin/storage/es/options.go b/plugin/storage/es/options.go
index 93bceddcf03..9afa5da6771 100644
--- a/plugin/storage/es/options.go
+++ b/plugin/storage/es/options.go
@@ -344,10 +344,10 @@ func initFromViper(cfg *namespaceConfig, v *viper.Viper) {
 	cfg.IndexPrefix = v.GetString(cfg.namespace + suffixIndexPrefix)
 
 	// TODO cfg.Indices does not have a separate flag
-	cfg.Indices.Spans.IndexPrefix = cfg.IndexPrefix
-	cfg.Indices.Services.IndexPrefix = cfg.IndexPrefix
-	cfg.Indices.Sampling.IndexPrefix = cfg.IndexPrefix
-	cfg.Indices.Dependencies.IndexPrefix = cfg.IndexPrefix
+	cfg.Indices.Spans.Prefix = cfg.IndexPrefix
+	cfg.Indices.Services.Prefix = cfg.IndexPrefix
+	cfg.Indices.Sampling.Prefix = cfg.IndexPrefix
+	cfg.Indices.Dependencies.Prefix = cfg.IndexPrefix
 
 	cfg.Tags.AllAsFields = v.GetBool(cfg.namespace + suffixTagsAsFieldsAll)
 	cfg.Tags.Include = v.GetString(cfg.namespace + suffixTagsAsFieldsInclude)