diff --git a/apps/openstmap/ChangeLog b/apps/openstmap/ChangeLog
index 10b29fd3b..1b0edaf34 100644
--- a/apps/openstmap/ChangeLog
+++ b/apps/openstmap/ChangeLog
@@ -30,4 +30,5 @@
 0.23: Bugfix: Enable Compass if needed
 0.24: Allow zooming by clicking the screen
 0.25: Enable scaled image filtering on 2v19+ firmware
-0.26: Ensure that when redrawing, we always cancel any in-progress track draw
\ No newline at end of file
+0.26: Ensure that when redrawing, we always cancel any in-progress track draw
+0.27: Display message if no map is installed
diff --git a/apps/openstmap/app.js b/apps/openstmap/app.js
index 1f4b0b8b7..d66936c29 100644
--- a/apps/openstmap/app.js
+++ b/apps/openstmap/app.js
@@ -268,7 +268,12 @@ function showMap() {
   }, btn: () => showMenu() });
 }
 
-showMap();
+
+if (m.maps.length === 0) {
+  E.showPrompt(/*LANG*/'Please upload a map first.', {buttons : {/*LANG*/"Ok":true}}).then(v => load());
+} else {
+  showMap();
+}
 
 // Write settings on exit via button
 setWatch(() => writeSettings(), BTN, { repeat: true, edge: "rising" });
diff --git a/apps/openstmap/metadata.json b/apps/openstmap/metadata.json
index 29278cbc3..75359d3fa 100644
--- a/apps/openstmap/metadata.json
+++ b/apps/openstmap/metadata.json
@@ -2,7 +2,7 @@
   "id": "openstmap",
   "name": "OpenStreetMap",
   "shortName": "OpenStMap",
-  "version": "0.26",
+  "version": "0.27",
   "description": "Loads map tiles from OpenStreetMap onto your Bangle.js and displays a map of where you are. Once installed this also adds map functionality to `GPS Recorder` and `Recorder` apps",
   "readme": "README.md",
   "icon": "app.png",
diff --git a/apps/openstmap/openstmap.js b/apps/openstmap/openstmap.js
index 0a36b829e..9c7c9697d 100644
--- a/apps/openstmap/openstmap.js
+++ b/apps/openstmap/openstmap.js
@@ -33,9 +33,11 @@ m.maps = require("Storage").list(/openstmap\.\d+\.json/).map(f=>{
 m.maps.sort((a,b) => b.scale-a.scale); // sort by scale so highest resolution is drawn last
 // we base our start position on the middle of the first map
 m.map = m.maps[0];
-m.scale = m.map.scale; // current scale (based on first map)
-m.lat = m.map.lat; // position of middle of screen
-m.lon = m.map.lon;  // position of middle of screen
+if (m.map) {
+  m.scale = m.map.scale; // current scale (based on first map)
+  m.lat = m.map.lat; // position of middle of screen
+  m.lon = m.map.lon;  // position of middle of screen
+}
 
 // return number of tiles drawn
 exports.draw = function() {