diff --git a/libraries/AP_HAL/CANIface.h b/libraries/AP_HAL/CANIface.h
index 0a0b8a614e..0d11ea1159 100644
--- a/libraries/AP_HAL/CANIface.h
+++ b/libraries/AP_HAL/CANIface.h
@@ -35,7 +35,10 @@ struct AP_HAL::CANFrame {
     static const uint8_t MaxDataLen = 8;
 
     uint32_t id;                ///< CAN ID with flags (above)
-    uint8_t data[MaxDataLen];
+    union {
+        uint8_t data[MaxDataLen];
+        uint32_t data_32[MaxDataLen/4];
+    };
     uint8_t dlc;                ///< Data Length Code
 
     CANFrame() :