diff --git a/pw_sync_threadx/public/pw_sync_threadx/binary_semaphore_native.h b/pw_sync_threadx/public/pw_sync_threadx/binary_semaphore_native.h
index e433435..cb4cb97 100644
--- a/pw_sync_threadx/public/pw_sync_threadx/binary_semaphore_native.h
+++ b/pw_sync_threadx/public/pw_sync_threadx/binary_semaphore_native.h
@@ -23,6 +23,8 @@
 using NativeBinarySemaphoreHandle = NativeBinarySemaphore&;
 
 inline constexpr ptrdiff_t kBinarySemaphoreMaxValue =
-    std::numeric_limits<ULONG>::max();
+    std::numeric_limits<ptrdiff_t>::max() < std::numeric_limits<ULONG>::max()
+        ? std::numeric_limits<ptrdiff_t>::max()
+        : std::numeric_limits<ULONG>::max();
 
 }  // namespace pw::sync::backend
diff --git a/pw_sync_threadx/public/pw_sync_threadx/counting_semaphore_native.h b/pw_sync_threadx/public/pw_sync_threadx/counting_semaphore_native.h
index d322a53..3db35a9 100644
--- a/pw_sync_threadx/public/pw_sync_threadx/counting_semaphore_native.h
+++ b/pw_sync_threadx/public/pw_sync_threadx/counting_semaphore_native.h
@@ -23,6 +23,8 @@
 using NativeCountingSemaphoreHandle = NativeCountingSemaphore&;
 
 inline constexpr ptrdiff_t kCountingSemaphoreMaxValue =
-    std::numeric_limits<ULONG>::max();
+    std::numeric_limits<ptrdiff_t>::max() < std::numeric_limits<ULONG>::max()
+        ? std::numeric_limits<ptrdiff_t>::max()
+        : std::numeric_limits<ULONG>::max();
 
 }  // namespace pw::sync::backend