diff --git a/bin/sanitycheck.js b/bin/sanitycheck.js
index e50256fb6..98fd1275f 100755
--- a/bin/sanitycheck.js
+++ b/bin/sanitycheck.js
@@ -58,6 +58,7 @@ const APP_KEYS = [
 ];
 const STORAGE_KEYS = ['name', 'url', 'content', 'evaluate', 'noOverwite', 'supports'];
 const DATA_KEYS = ['name', 'wildcard', 'storageFile', 'url', 'content', 'evaluate'];
+const SUPPORTS_DEVICES = ["BANGLEJS","BANGLEJS2"]; // device IDs allowed for 'supports'
 const FORBIDDEN_FILE_NAME_CHARS = /[,;]/; // used as separators in appid.info
 const VALID_DUPLICATES = [ '.tfmodel', '.tfnames' ];
 const GRANDFATHERED_ICONS = ["s7clk",  "snek", "astral", "alpinenav", "slomoclock", "arrow", "pebble", "rebble"];
@@ -90,7 +91,7 @@ apps.forEach((app,appIdx) => {
   if (!Array.isArray(app.supports)) ERROR(`App ${app.id} has no 'supports' field or it's not an array`);
   else {
     app.supports.forEach(dev => {
-      if (!["BANGLEJS","BANGLEJS2"].includes(dev))
+      if (!SUPPORTS_DEVICES.includes(dev))
         ERROR(`App ${app.id} has unknown device in 'supports' field - ${dev}`);
     });
   }
@@ -140,6 +141,13 @@ apps.forEach((app,appIdx) => {
     if (char) ERROR(`App ${app.id} storage file ${file.name} contains invalid character "${char[0]}"`)
     if (fileNames.includes(file.name) && !file.supports)  // assume that there aren't duplicates if 'supports' is set
       ERROR(`App ${app.id} file ${file.name} is a duplicate`);
+    if (file.supports && !Array.isArray(file.supports))
+      ERROR(`App ${app.id} file ${file.name} supports field must be an array`);
+    if (file.supports)
+      file.supports.forEach(dev => {
+        if (!SUPPORTS_DEVICES.includes(dev))
+          ERROR(`App ${app.id} file ${file.name} has unknown device in 'supports' field - ${dev}`);
+      });
     fileNames.push(file.name);
     allFiles.push({app: app.id, file: file.name});
     if (file.url) if (!fs.existsSync(appDir+file.url)) ERROR(`App ${app.id} file ${file.url} doesn't exist`);
@@ -271,7 +279,8 @@ while(fileA=allFiles.pop()) {
     if (globA.test(nameB)||globB.test(nameA)) {
       if (isGlob(nameA)||isGlob(nameB))
         ERROR(`App ${fileB.app} ${typeB} file ${nameB} matches app ${fileA.app} ${typeB} file ${nameA}`)
-      else WARN(`App ${fileB.app} ${typeB} file ${nameB} is also listed as ${typeA} file for app ${fileA.app}`)
+      else if (fileA.app != fileB.app)
+        WARN(`App ${fileB.app} ${typeB} file ${nameB} is also listed as ${typeA} file for app ${fileA.app}`)
     }
   })
 }