diff --git a/cmds/cmds.ts b/cmds/cmds.ts
index 33e77ff6..c862c7a6 100644
--- a/cmds/cmds.ts
+++ b/cmds/cmds.ts
@@ -13,10 +13,13 @@ export function deployCoreAsync(res: ts.pxtc.CompileResult) {
     return getBitDrivesAsync()
         .then(drives => {
             if (drives.length == 0) {
-                console.log("cannot find any drives to deploy to")
-            } else {
-                console.log(`copy ${ts.pxtc.BINARY_HEX} to ` + drives.join(", "))
+                let msg = "cannot find any drives to deploy to";
+                console.log(msg);
+                return Promise.reject(new Error(msg));
             }
+
+            console.log(`copy ${ts.pxtc.BINARY_HEX} to ` + drives.join(", "))
+
             return Promise.map(drives, d =>
                 writeFileAsync(d + ts.pxtc.BINARY_HEX, res.outfiles[ts.pxtc.BINARY_HEX])
                     .then(() => {