diff --git a/test/cpp/thread_manager/thread_manager_test.cc b/test/cpp/thread_manager/thread_manager_test.cc
index 35c8d5d0880d0e6f2eb1970a7d78dce9a98d9e02..e1a03666f0b4ec407d2c40eb264860f32be51f90 100644
--- a/test/cpp/thread_manager/thread_manager_test.cc
+++ b/test/cpp/thread_manager/thread_manager_test.cc
@@ -118,7 +118,7 @@ void ThreadManagerTest::PerformTest() {
 
   // The number of times DoWork() was called is equal to the number of times
   // WORK_FOUND was returned
-  gpr_log(GPR_DEBUG, "DoWork() called %ld times",
+  gpr_log(GPR_DEBUG, "DoWork() called %" PRIdPTR " times",
           gpr_atm_no_barrier_load(&num_do_work_));
   GPR_ASSERT(gpr_atm_no_barrier_load(&num_do_work_) ==
              gpr_atm_no_barrier_load(&num_work_found_));