diff --git a/libs/microbit-radio/radio.cpp b/libs/microbit-radio/radio.cpp
index 2bcbfbc0..83ff0eb9 100644
--- a/libs/microbit-radio/radio.cpp
+++ b/libs/microbit-radio/radio.cpp
@@ -114,19 +114,19 @@ namespace radio {
         uBit.serial.send("{");
         if (length >= 4) {
             memcpy(&value, bytes, 4);
-            uBit.serial.send("v:"); uBit.serial.send(value);
+            uBit.serial.send("\"v\":"); uBit.serial.send(value);
             if(length >= 8) {
                 memcpy(&value, bytes + 4, 4);
-                uBit.serial.send(",t:"); uBit.serial.send(value);                
+                uBit.serial.send(",\"t\":"); uBit.serial.send(value);                
                 if (length >= 12) {
                     memcpy(&value, bytes + 8, 4);
-                    uBit.serial.send(",s:"); uBit.serial.send(value);                                    
+                    uBit.serial.send(",\"s\":"); uBit.serial.send(value);                                    
                     if (length >= 13) {
                         char name[MAX_FIELD_NAME_LENGTH+1];
                         uint8_t len = min(MAX_FIELD_NAME_LENGTH, bytes[12]);
                         memcpy(name, bytes + 13, len);
                         name[len] = 0;
-                        uBit.serial.send(",n:\""); uBit.serial.send(name); uBit.serial.send("\"");                                    
+                        uBit.serial.send(",\"n\":\""); uBit.serial.send(name); uBit.serial.send("\"");                                    
                     }
                 }
             }