(clang) const void* const pointer confusion

c/src/main.c

@@ -2,6 +2,9 @@
 
 int main(void)
 {
-    printf("hello world");
+    const void* pointer = (void*)(1000);
+    printf("original pointer = %p\n", pointer);
+    pointer = NULL;
+    printf("changed pointer = %p\n", pointer);
     return 0;
 }