diff --git a/source/common/common/posix/thread_impl.cc b/source/common/common/posix/thread_impl.cc
index a070ad278c38..66ba6f2d5c78 100644
--- a/source/common/common/posix/thread_impl.cc
+++ b/source/common/common/posix/thread_impl.cc
@@ -51,13 +51,12 @@ void setThreadPriority(const int64_t tid, const int priority) {
   // the thread priority on Apple platforms, and directly invoking `setpriority()` on iOS fails with
   // permissions issues, as discovered through manual testing.
   Class nsthread = objc_getClass("NSThread");
-  if (nsthread != nullptr) {
-    id (*getCurrentNSThread)(Class, SEL) = reinterpret_cast<id (*)(Class, SEL)>(objc_msgSend);
-    id current_thread = getCurrentNSThread(nsthread, sel_registerName("currentThread"));
-    void (*setNSThreadPriority)(id, SEL, double) =
-        reinterpret_cast<void (*)(id, SEL, double)>(objc_msgSend);
-    setNSThreadPriority(current_thread, sel_registerName("setThreadPriority:"), priority);
-  }
+  id (*getCurrentNSThread)(Class, SEL) = reinterpret_cast<id (*)(Class, SEL)>(objc_msgSend);
+  id current_thread = getCurrentNSThread(nsthread, sel_registerName("currentThread"));
+  void (*setNSThreadPriority)(id, SEL, double) =
+      reinterpret_cast<void (*)(id, SEL, double)>(objc_msgSend);
+  double ns_priority = static_cast<double>(priority) / 100.0;
+  setNSThreadPriority(current_thread, sel_registerName("setThreadPriority:"), ns_priority);
 #else
 #error "Enable and test pthread id retrieval code for you arch in pthread/thread_impl.cc"
 #endif
diff --git a/test/common/common/thread_test.cc b/test/common/common/thread_test.cc
index 11cd78fe68f3..acfbe267c034 100644
--- a/test/common/common/thread_test.cc
+++ b/test/common/common/thread_test.cc
@@ -278,7 +278,7 @@ TEST(PosixThreadTest, Joinable) {
 TEST(PosixThreadTest, ThreadPriority) {
   auto thread_factory = PosixThreadFactory::create();
   Options options;
-  options.priority_ = 10;
+  options.priority_ = 15;
   double thread_priority;
   auto thread = thread_factory->createThread(
       [&]() { thread_priority = thread_factory->currentThreadPriority(); }, options,
@@ -288,6 +288,16 @@ TEST(PosixThreadTest, ThreadPriority) {
   EXPECT_EQ(thread_priority, options.priority_);
 }
 
+TEST(PosixThreadTest, OptionsNoPriority) {
+  auto thread_factory = PosixThreadFactory::create();
+  Options options;
+  auto thread = thread_factory->createThread([&]() {}, options, /* crash_on_failure= */ true);
+
+  EXPECT_TRUE(thread->joinable());
+  thread->join();
+  EXPECT_FALSE(thread->joinable());
+}
+
 class PosixThreadFactoryFailCreate : public PosixThreadFactory {
 protected:
   int createPthread(ThreadHandle*) override { return 1; }