diff --git a/sensors/builder.hpp b/sensors/builder.hpp
index 688a931..236fee7 100644
--- a/sensors/builder.hpp
+++ b/sensors/builder.hpp
@@ -6,9 +6,14 @@
 #include <map>
 #include <string>
 
+namespace pid_control
+{
+
 /**
  * Build the sensors and associate them with a SensorManager.
  */
 SensorManager
     buildSensors(const std::map<std::string, struct conf::SensorConfig>& config,
                  sdbusplus::bus::bus& passive, sdbusplus::bus::bus& host);
+
+} // namespace pid_control