diff --git a/tasmota/xsns_75_prometheus.ino b/tasmota/xsns_75_prometheus.ino
index bbdb303c5..0b0251229 100644
--- a/tasmota/xsns_75_prometheus.ino
+++ b/tasmota/xsns_75_prometheus.ino
@@ -57,6 +57,7 @@ String FormatMetricName(const char *metric) {  // cleanup spaces and uppercases
   String formatted = metric;
   formatted.toLowerCase();
   formatted.replace(" ", "_");
+  formatted.replace(".", "_");
   return formatted;
 }