diff --git a/libc/bionic/pthread_mutex.cpp b/libc/bionic/pthread_mutex.cpp
index e5f2a31..f1f7294 100644
--- a/libc/bionic/pthread_mutex.cpp
+++ b/libc/bionic/pthread_mutex.cpp
@@ -943,11 +943,16 @@
 int pthread_mutex_destroy(pthread_mutex_t* mutex_interface) {
     pthread_mutex_internal_t* mutex = __get_internal_mutex(mutex_interface);
     uint16_t old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
+    if (old_state == 0xffff) {
+        // The mutex has been destroyed.
+        return EBUSY;
+    }
     uint16_t mtype  = (old_state & MUTEX_TYPE_MASK);
     if (mtype == MUTEX_TYPE_BITS_WITH_PI) {
         int result = PIMutexDestroy(mutex->ToPIMutex());
         if (result == 0) {
             mutex->FreePIMutex();
+            atomic_store(&mutex->state, 0xffff);
         }
         return result;
     }
diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index 40059d0..8ac5223 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -1672,6 +1672,7 @@
 
   void destroy() {
     ASSERT_EQ(0, pthread_mutex_destroy(&lock));
+    ASSERT_EQ(EBUSY, pthread_mutex_destroy(&lock));
   }
 
   DISALLOW_COPY_AND_ASSIGN(PthreadMutex);