diff --git a/pw_build/CMakeLists.txt b/pw_build/CMakeLists.txt
index 3b8df7d8f7..6ffeb89574 100644
--- a/pw_build/CMakeLists.txt
+++ b/pw_build/CMakeLists.txt
@@ -119,7 +119,7 @@ pw_add_library_generic(pw_build.pedantic_warnings INTERFACE
     "-Wno-gnu-zero-variadic-macro-arguments"
 
     # TODO: b/333712899 - Enable C23 extension warnings.
-    "-Wno-c23-extensions"
+    "-Wno-c2x-extensions"
 
     # TODO: b/335021928 - Enable C++ 20 extension warnings.
     "-Wno-c++20-extensions"
diff --git a/pw_kvs/public/pw_kvs/flash_memory.h b/pw_kvs/public/pw_kvs/flash_memory.h
index 1ec16cbf13..85ba5a9dcc 100644
--- a/pw_kvs/public/pw_kvs/flash_memory.h
+++ b/pw_kvs/public/pw_kvs/flash_memory.h
@@ -24,6 +24,7 @@
 #include "pw_span/span.h"
 #include "pw_status/status.h"
 #include "pw_status/status_with_size.h"
+#include "cmsis_os2.h"
 
 #if PW_CXX_STANDARD_IS_SUPPORTED(17)  // Requires C++17 for pw::Result
 #include "pw_stream/seek.h"
@@ -132,6 +133,8 @@ class FlashMemory {
     return erased_memory_content_;
   }
 
+  virtual void SetBlockingMode(bool en_blocking, osThreadId_t task_handle) = 0;
+
  private:
   const uint32_t sector_size_;
   const uint32_t flash_sector_count_;