diff --git a/codes/c/chapter_sorting/counting_sort.c b/codes/c/chapter_sorting/counting_sort.c
index dea63303c..73ba54f0a 100644
--- a/codes/c/chapter_sorting/counting_sort.c
+++ b/codes/c/chapter_sorting/counting_sort.c
@@ -18,7 +18,7 @@ void countingSortNaive(int nums[], int size) {
     }
     // 2. 统计各数字的出现次数
     // counter[num] 代表 num 的出现次数
-    int *counter = malloc(sizeof(int) * size);
+    int *counter = malloc(sizeof(int) * m);
     for (int i = 0; i < size; i++) {
         counter[nums[i]]++;
     }
@@ -43,7 +43,7 @@ void countingSort(int nums[], int size) {
     }
     // 2. 统计各数字的出现次数
     // counter[num] 代表 num 的出现次数
-    int *counter = malloc(sizeof(int) * size);
+    int *counter = malloc(sizeof(int) * m);
     for (int i = 0; i < size; i++) {
         counter[nums[i]]++;
     }