diff --git a/libfprint/drivers/vfs301_proto.c b/libfprint/drivers/vfs301_proto.c
index c272659..bcd09e9 100644
--- a/libfprint/drivers/vfs301_proto.c
+++ b/libfprint/drivers/vfs301_proto.c
@@ -438,7 +438,7 @@ img_process_data (int first_block, FpDeviceVfs301 *dev, const guint8 *buf, int l
     usb_send (dev, data, len, NULL); \
   }
 
-#define RAW_DATA(x) x, sizeof (x)
+#define RAW_DATA(x) g_memdup (x, sizeof (x)), sizeof (x)
 
 #define IS_VFS301_FP_SEQ_START(b) ((b[0] == 0x01) && (b[1] == 0xfe))