diff --git a/FirmwareMetadataSection.c b/FirmwareMetadataSection.c
index 088b357..fe2d999 100644
--- a/FirmwareMetadataSection.c
+++ b/FirmwareMetadataSection.c
@@ -20,11 +20,11 @@
 #define DEF_FINGER_YEAR FINGER_YEAR
 #define DEF_FINGER_MONTH  FINGER_MONTH
 #define DEF_FINGER_DAY  FINGER_DAY
-#define DEF_FINGER_TESTER_SERIAL FINGER_TESTER_SERIAL " (" VERSION_RANDOM_BUILD_IDENTIFIER ")"
+#define DEF_FINGER_TESTER_SERIAL FINGER_TESTER_SERIAL "_(" VERSION_RANDOM_BUILD_IDENTIFIER ")"
 
 volatile const uint32_t META_FW_CRC __attribute__((section (".meta_fw_crc"))) = 0;
 
-volatile const uint8_t META_FW_NAME_SIZE __attribute__((section (".meta_fw_name_size"))) = sizeof(DEF_FINGER_TESTER_SERIAL);
+volatile const uint8_t META_FW_NAME_SIZE __attribute__((section (".meta_fw_name_size"))) = sizeof(DEF_FINGER_TESTER_SERIAL) - 1;
 volatile const char META_FW_NAME[sizeof(DEF_FINGER_TESTER_SERIAL) - 1] __attribute__((section (".meta_fw_name"))) = DEF_FINGER_TESTER_SERIAL;
 
 volatile const char META_INTERNAL_HW_YEAR __attribute__((section (".meta_internal_hw_year"))) = DEF_INTERNAL_HW_YEAR;