diff --git a/app/src/google/java/com/geeksville/mesh/ui/map/components/CustomMapLayersSheet.kt b/app/src/google/java/com/geeksville/mesh/ui/map/components/CustomMapLayersSheet.kt
index c86613e00..6f6908c93 100644
--- a/app/src/google/java/com/geeksville/mesh/ui/map/components/CustomMapLayersSheet.kt
+++ b/app/src/google/java/com/geeksville/mesh/ui/map/components/CustomMapLayersSheet.kt
@@ -60,6 +60,13 @@ fun CustomMapLayersSheet(
             )
             HorizontalDivider()
         }
+        item {
+            Text(
+                modifier = Modifier.padding(start = 16.dp, end = 16.dp, top = 8.dp, bottom = 0.dp),
+                text = stringResource(R.string.map_layer_formats),
+                style = MaterialTheme.typography.bodySmall,
+            )
+        }
 
         if (mapLayers.isEmpty()) {
             item {
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index a5907036b..6939fe358 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -777,6 +777,7 @@
     <string name="map_type_terrain">Terrain</string>
     <string name="map_type_hybrid">Hybrid</string>
     <string name="manage_map_layers">Manage Map Layers</string>
+    <string name="map_layer_formats">Custom layers support .kml or .kmz files.</string>
     <string name="map_layers_title">Map Layers</string>
     <string name="no_map_layers_loaded">No custom layers loaded.</string>
     <string name="add_layer_button">Add Layer</string>