diff --git a/damus-c/damus.c b/damus-c/damus.c
index da1980e4..48a2fbe4 100644
--- a/damus-c/damus.c
+++ b/damus-c/damus.c
@@ -211,11 +211,11 @@ static int parse_invoice(struct cursor *cur, struct block *block) {
     const u8 *start, *end;
     char *fail;
     struct bolt11 *bolt11;
-    start = cur->p;
-    
     // optional
     parse_str(cur, "lightning:");
     
+    start = cur->p;
+    
     if (!parse_str(cur, "lnbc"))
         return 0;