diff --git a/test/pthread/main.c b/test/pthread/main.c
index 1fec331a..852e47e0 100644
--- a/test/pthread/main.c
+++ b/test/pthread/main.c
@@ -6,36 +6,76 @@
  * Child threads
  */
 
-#define NTHREADS            4
-#define STACK_SIZE          (8 * 1024)
+#define NTHREADS                (4)
+#define STACK_SIZE              (8 * 1024)
 
-static void* thread_func(void* arg) {
-    int* tid = arg;
-    printf("tid = %d\n", *tid);
+#define LOCAL_COUNT             (100000L)
+#define EXPECTED_GLOBAL_COUNT   (LOCAL_COUNT * NTHREADS)
+
+struct thread_arg {
+    int                         ti;
+    long                        local_count;
+    volatile long*              global_count;
+    pthread_mutex_t*            mutex;
+};
+
+static void* thread_func(void* _arg) {
+    struct thread_arg* arg = _arg;
+    printf("Thread #%d: started\n", arg->ti);
+    for (long i = 0; i < arg->local_count; i++) {
+        pthread_mutex_lock(arg->mutex);
+        (*arg->global_count)++;
+        pthread_mutex_unlock(arg->mutex);
+    }
+    printf("Thread #%d: completed\n", arg->ti);
     return NULL;
 }
 
 int main(int argc, const char* argv[]) {
+    /*
+     * Multiple threads are to increase a global counter concurrently
+     */
+    volatile long global_count = 0;
     pthread_t threads[NTHREADS];
-    int thread_data[NTHREADS];
-
-    printf("Creating %d threads...", NTHREADS);
+    struct thread_arg thread_args[NTHREADS];
+    /*
+     * Protect the counter with a mutex
+     */
+    pthread_mutex_t mutex;
+    pthread_mutex_init(&mutex, NULL);
+    /*
+     * Start the threads
+     */
     for (int ti = 0; ti < NTHREADS; ti++) {
-        thread_data[ti] = ti;
-        if (pthread_create(&threads[ti], NULL, thread_func, &thread_data[ti]) < 0) {
+        struct thread_arg* thread_arg = &thread_args[ti];
+        thread_arg->ti = ti;
+        thread_arg->local_count = LOCAL_COUNT;
+        thread_arg->global_count = &global_count;
+        thread_arg->mutex = &mutex;
+
+        if (pthread_create(&threads[ti], NULL, thread_func, thread_arg) < 0) {
             printf("ERROR: pthread_create failed (ti = %d)\n", ti);
             return -1;
         }
     }
-    printf("done.\n");
-
-    printf("Waiting for %d threads to exit...", NTHREADS);
+    /*
+     * Wait for the threads to finish
+     */
     for (int ti = 0; ti < NTHREADS; ti++) {
         if (pthread_join(threads[ti], NULL) < 0) {
             printf("ERROR: pthread_join failed (ti = %d)\n", ti);
             return -1;
         }
     }
-    printf("done.\n");
+    /*
+     * Check the correctness of the concurrent counter
+     */
+    if (global_count != EXPECTED_GLOBAL_COUNT) {
+        printf("ERROR: incorrect global_count (actual = %ld, expected = %ld)\n",
+                global_count, EXPECTED_GLOBAL_COUNT);
+        return -1;
+    }
+
+    pthread_mutex_destroy(&mutex);
     return 0;
 }