diff --git a/tools/bt.cpp b/tools/bt.cpp
index de26b27..da582d4 100644
--- a/tools/bt.cpp
+++ b/tools/bt.cpp
@@ -1,7 +1,12 @@
 #include "bt.hpp"
 
+namespace host_tool
+{
+
 bool BtDataHandler::sendContents(const std::string& input,
                                  std::uint16_t session)
 {
     return false;
 }
+
+} // namespace host_tool