diff --git a/locales/en-US/app.ftl b/locales/en-US/app.ftl
index b8774a09ee..5625f479b5 100644
--- a/locales/en-US/app.ftl
+++ b/locales/en-US/app.ftl
@@ -1039,6 +1039,12 @@ TrackPower--tooltip-average-power-watt = { $value } W
 TrackPower--tooltip-average-power-milliwatt = { $value } mW
   .label = Average power in the current selection
 
+# This is used in the tooltip when the power value uses the microwatt unit.
+# Variables:
+#   $value (String) - the power value at this location
+TrackPower--tooltip-average-power-microwatt = { $value } μW
+  .label = Average power in the current selection
+
 # This is used in the tooltip when the energy used in the current range uses the
 # kilowatt-hour unit.
 # Variables: