diff --git a/solaredge.py b/solaredge.py
index b6a2b8d..9437d69 100755
--- a/solaredge.py
+++ b/solaredge.py
@@ -123,7 +123,7 @@ def format_metrics(entries):
             yield "# HELP {} {}\n".format(metric, md[1])
 
         for (time, metric, attrs, value) in collected[metric]:
-            time_s = time.timestamp()
+            time_s = int(time.timestamp() * 1000)
             attr_s = ""
             if attrs:
                 attr_s = "{" + ','.join('{}="{}"'.format(k, attrs[k]) for k in attrs ) + "}"