diff --git a/src/urclock.c b/src/urclock.c
index cec8e038..78520365 100644
--- a/src/urclock.c
+++ b/src/urclock.c
@@ -1156,6 +1156,7 @@ static void guessblstart(const PROGRAMMER *pgm, const AVRPART *p) {
     {  256, 0, 0xaa62bafc, 0xaa62bafc }, // picobootArduino8v3rc1.hex
     {  256, 0, 0x56263965, 0x56263965 }, // picobootSTK500-168p.hex
     {  512, 0, 0x3242ddd3, 0x5ba5f5f6 }, // picobootSTK500-328p.hex
+    { 3072, 0, 0x3242ddd3, 0xd3347c5d }, // optiboot_lgt8f328p.hex
   };
 
   uint8_t buf[4096], b128[128];