diff --git a/host/lib/include/uhdlib/usrp/common/ltc5594.hpp b/host/lib/include/uhdlib/usrp/common/ltc5594.hpp
index 55df5933e..a63ed03a4 100644
--- a/host/lib/include/uhdlib/usrp/common/ltc5594.hpp
+++ b/host/lib/include/uhdlib/usrp/common/ltc5594.hpp
@@ -9,6 +9,7 @@
 #include <uhd/types/time_spec.hpp>
 #include <functional>
 #include <memory>
+#include <string>
 
 //! Control interface for an LTC5594 I/Q Demodulator
 class ltc5594_iface