diff --git a/nemu/tests/expr_test.c b/nemu/tests/expr_test.c
index 181d011..c5f874b 100644
--- a/nemu/tests/expr_test.c
+++ b/nemu/tests/expr_test.c
@@ -173,7 +173,7 @@ START_TEST(test_expr_plain_register) {
   uint32_t value;
   // NOTE: need to fix this if want to support more arch
   buf[0] = '$';
-  for (i = 1; i < 32; i++) {
+  for (i = 0; i < 32; i++) {
     ck_assert(strncpy(buf + 1, regs[i], 10) != NULL);
     gpr(i) = i;
     yy_scan_string(buf);