diff --git a/nemu/src/utils/elf-parser.c b/nemu/src/utils/elf-parser.c
index 1e536f4..874ccd3 100644
--- a/nemu/src/utils/elf-parser.c
+++ b/nemu/src/utils/elf-parser.c
@@ -19,7 +19,7 @@ static int cmp_func_t(const void *a, const void *b) {
 func_t *get_func(vaddr_t addr) {
   int l = 0, r = func_table_len - 1;
   while(l <= r) {
-    int mid = l + (r - l) / 2;
+    int mid = (l + r) / 2;
     if(func_table[mid].start <= addr)  l = mid + 1;
     else r = mid - 1;
   }