diff --git a/src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_tracking_cc.cc b/src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_tracking_cc.cc
index 97c92225b..2b2a02ed1 100644
--- a/src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_tracking_cc.cc
+++ b/src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_tracking_cc.cc
@@ -41,6 +41,7 @@
 #include <sstream>
 #include <boost/lexical_cast.hpp>
 #include <gnuradio/io_signature.h>
+#include <gnuradio/fxpt.h>  // fixed point sine and cosine
 #include <glog/logging.h>
 #include "gnss_synchro.h"
 #include "gps_sdr_signal_processing.h"