diff --git a/src/xpath.c b/src/xpath.c
index 968cb19..d1e7bfb 100644
--- a/src/xpath.c
+++ b/src/xpath.c
@@ -2078,7 +2078,7 @@
     case 6:
         if (!strncmp(&exp->expr[exp->tok_pos[*exp_idx]], "concat", 6)) {
             min_arg_count = 2;
-            max_arg_count = 3;
+            max_arg_count = INT_MAX;
         } else if (!strncmp(&exp->expr[exp->tok_pos[*exp_idx]], "number", 6)) {
             min_arg_count = 0;
             max_arg_count = 1;