diff --git a/src/DfuTransportNoble.js b/src/DfuTransportNoble.js
index cb09773..cf78130 100644
--- a/src/DfuTransportNoble.js
+++ b/src/DfuTransportNoble.js
@@ -65,7 +65,7 @@ export default class DfuTransportNoble extends DfuTransportPrn {
         this.dfuPacketCharacteristic = undefined;
 
         // Hard-coded BLE MTU
-        this.mtu = 23;
+        this.mtu = 20;
     }