diff --git a/include/spdlog/sinks/stdout_sinks-inl.h b/include/spdlog/sinks/stdout_sinks-inl.h
index fff292c2..dcb21d84 100644
--- a/include/spdlog/sinks/stdout_sinks-inl.h
+++ b/include/spdlog/sinks/stdout_sinks-inl.h
@@ -23,7 +23,7 @@
 
     #include <io.h>     // _get_osfhandle(..)
     #include <stdio.h>  // _fileno(..)
-#endif                  // WIN32
+#endif                  // _WIN32
 
 namespace spdlog {
 
@@ -45,7 +45,7 @@ SPDLOG_INLINE stdout_sink_base<ConsoleMutex>::stdout_sink_base(FILE *file)
     if (handle_ == INVALID_HANDLE_VALUE && file != stdout && file != stderr) {
         throw_spdlog_ex("spdlog::stdout_sink_base: _get_osfhandle() failed", errno);
     }
-#endif  // WIN32
+#endif  // _WIN32
 }
 
 template <typename ConsoleMutex>
@@ -69,7 +69,7 @@ SPDLOG_INLINE void stdout_sink_base<ConsoleMutex>::log(const details::log_msg &m
     memory_buf_t formatted;
     formatter_->format(msg, formatted);
     details::os::fwrite_bytes(formatted.data(), formatted.size(), file_);
-#endif                // WIN32
+#endif                // _WIN32
     ::fflush(file_);  // flush every line to terminal
 }