diff --git a/include/spdlog/sinks/null_sink.h b/include/spdlog/sinks/null_sink.h
index 857e31f2..44a45a3e 100644
--- a/include/spdlog/sinks/null_sink.h
+++ b/include/spdlog/sinks/null_sink.h
@@ -20,7 +20,7 @@ protected:
     void flush_() override {}
 };
 
-using null_sink_mt = null_sink<std::mutex>;
+using null_sink_mt = null_sink<details::null_mutex>;
 using null_sink_st = null_sink<details::null_mutex>;
 
 } // namespace sinks
diff --git a/include/spdlog/sinks/rotating_file_sink.h b/include/spdlog/sinks/rotating_file_sink.h
index 45fa3bd1..f8c49e75 100644
--- a/include/spdlog/sinks/rotating_file_sink.h
+++ b/include/spdlog/sinks/rotating_file_sink.h
@@ -5,6 +5,7 @@
 
 #include "spdlog/sinks/base_sink.h"
 #include "spdlog/details/file_helper.h"
+#include "spdlog/details/null_mutex.h"
 #include "spdlog/details/synchronous_factory.h"
 
 #include <chrono>
diff --git a/include/spdlog/sinks/syslog_sink.h b/include/spdlog/sinks/syslog_sink.h
index ce216d09..42dbda0f 100644
--- a/include/spdlog/sinks/syslog_sink.h
+++ b/include/spdlog/sinks/syslog_sink.h
@@ -4,6 +4,7 @@
 #pragma once
 
 #include "spdlog/sinks/base_sink.h"
+#include "spdlog/details/null_mutex.h"
 
 #include <array>
 #include <string>
diff --git a/include/spdlog/sinks/systemd_sink.h b/include/spdlog/sinks/systemd_sink.h
index da1c3e2c..ae8ace75 100644
--- a/include/spdlog/sinks/systemd_sink.h
+++ b/include/spdlog/sinks/systemd_sink.h
@@ -4,6 +4,7 @@
 #pragma once
 
 #include "spdlog/sinks/base_sink.h"
+#include "spdlog/details/null_mutex.h"
 #include "spdlog/details/synchronous_factory.h"
 
 #include <array>