diff --git a/agent/reader.go b/agent/reader.go
index 32d989e..1dc5a45 100644
--- a/agent/reader.go
+++ b/agent/reader.go
@@ -217,6 +217,10 @@ func convert(item *types.Sample) *prompb.TimeSeries {
 
 	// add other labels
 	for k, v := range item.Labels {
+		k = strings.Replace(k, "/", "_", -1)
+		k = strings.Replace(k, ".", "_", -1)
+		k = strings.Replace(k, "-", "_", -1)
+		k = strings.Replace(k, " ", "_", -1)
 		pt.Labels = append(pt.Labels, &prompb.Label{
 			Name:  k,
 			Value: v,