diff --git a/radio/src/pulses/pxx2.h b/radio/src/pulses/pxx2.h
index a87bdc8c5..61efa2666 100644
--- a/radio/src/pulses/pxx2.h
+++ b/radio/src/pulses/pxx2.h
@@ -261,19 +261,19 @@ class Pxx2Pulses: public PxxPulses<Pxx2Transport> {
     }
 };
 
-union PXX2Version
+PACK(struct PXX2Version
 {
   uint8_t major;
   uint8_t minor:4;
   uint8_t revision:4;
-};
+});
 
-struct PXX2HardwareInformation
+PACK(struct PXX2HardwareInformation
 {
   uint8_t modelID;
   PXX2Version hwVersion;
   PXX2Version swVersion;
   uint8_t variant;
-};
+});
 
 #endif