diff --git a/src/serialupdi.c b/src/serialupdi.c
index 9498f6f2..0561bb1f 100644
--- a/src/serialupdi.c
+++ b/src/serialupdi.c
@@ -543,16 +543,23 @@ static int serialupdi_write_userrow(const PROGRAMMER *pgm, const AVRPART *p, con
     return -1;
   }
 
-  if(n_bytes <= UPDI_MAX_REPEAT_SIZE) {
-    if(updi_write_data(pgm, m->offset + addr, m->buf + addr, n_bytes) < 0) {
-      pmsg_error("writing USER ROW failed\n");
-      return -1;
-    }
-  } else {
-    if(updi_write_data_words(pgm, m->offset + addr, m->buf + addr, n_bytes) < 0) {
+  unsigned int remaining_bytes = n_bytes;
+  unsigned int addr_offset = 0;
+  unsigned int current_write_size = 0;
+
+  while (remaining_bytes > 0) {
+    if (remaining_bytes <= UPDI_MAX_REPEAT_SIZE) {
+      current_write_size = remaining_bytes;
+    } else {
+      current_write_size = UPDI_MAX_REPEAT_SIZE;
+    }
+    pmsg_debug("Writing %d bytes to address 0x%06x in USERROW", current_write_size, m->offset + addr + addr_offset);
+    if(updi_write_data(pgm, m->offset + addr + addr_offset, m->buf + addr + addr_offset, current_write_size) < 0) {
       pmsg_error("writing USER ROW failed\n");
       return -1;
     }
+    addr_offset+=current_write_size;
+    remaining_bytes-=current_write_size;
   }
 
   if(updi_write_cs(pgm, UPDI_ASI_SYS_CTRLA,