diff --git a/src/arch/Lights/LightsDriver_PacDrive.h b/src/arch/Lights/LightsDriver_PacDrive.h
index ad84de68f3..4ddaeff171 100644
--- a/src/arch/Lights/LightsDriver_PacDrive.h
+++ b/src/arch/Lights/LightsDriver_PacDrive.h
@@ -55,7 +55,7 @@ typedef union
 		bool led14 : 1;
 		bool led15 : 1;
 		bool led16 : 1;
-	};
+	} __attribute__((packed));
 	uint16_t raw;
 } pacdrive_leds_t;
 
@@ -67,7 +67,7 @@ typedef union
 		uint8_t pad0;
 		uint8_t pad1;
 		pacdrive_leds_t leds;
-	};
+	} __attribute__((packed));
 	uint8_t raw_state[PACDRIVE_HIDREPORT_SIZE];
 } pacdrive_state_t;