diff --git a/src/core/system_parameters/rtcm.cc b/src/core/system_parameters/rtcm.cc
index fc7fc889f..8a3e55994 100644
--- a/src/core/system_parameters/rtcm.cc
+++ b/src/core/system_parameters/rtcm.cc
@@ -1531,7 +1531,6 @@ std::string Rtcm::print_MSM_1( const Gps_Ephemeris & gps_eph,
         unsigned int clock_steering_indicator,
         unsigned int external_clock_indicator,
         int smooth_int,
-        bool sync_flag,
         bool divergence_free,
         bool more_messages)
 {
@@ -1718,7 +1717,6 @@ std::string Rtcm::print_MSM_2( const Gps_Ephemeris & gps_eph,
         unsigned int clock_steering_indicator,
         unsigned int external_clock_indicator,
         int smooth_int,
-        bool sync_flag,
         bool divergence_free,
         bool more_messages)
 {
@@ -1815,7 +1813,6 @@ std::string Rtcm::print_MSM_3( const Gps_Ephemeris & gps_eph,
         unsigned int clock_steering_indicator,
         unsigned int external_clock_indicator,
         int smooth_int,
-        bool sync_flag,
         bool divergence_free,
         bool more_messages)
 {
@@ -1914,7 +1911,6 @@ std::string Rtcm::print_MSM_4( const Gps_Ephemeris & gps_eph,
         unsigned int clock_steering_indicator,
         unsigned int external_clock_indicator,
         int smooth_int,
-        bool sync_flag,
         bool divergence_free,
         bool more_messages)
 {
@@ -2056,7 +2052,6 @@ std::string Rtcm::print_MSM_5( const Gps_Ephemeris & gps_eph,
         unsigned int clock_steering_indicator,
         unsigned int external_clock_indicator,
         int smooth_int,
-        bool sync_flag,
         bool divergence_free,
         bool more_messages)
 {
@@ -2208,7 +2203,6 @@ std::string Rtcm::print_MSM_6( const Gps_Ephemeris & gps_eph,
         unsigned int clock_steering_indicator,
         unsigned int external_clock_indicator,
         int smooth_int,
-        bool sync_flag,
         bool divergence_free,
         bool more_messages)
 {
@@ -2311,7 +2305,6 @@ std::string Rtcm::print_MSM_7( const Gps_Ephemeris & gps_eph,
         unsigned int clock_steering_indicator,
         unsigned int external_clock_indicator,
         int smooth_int,
-        bool sync_flag,
         bool divergence_free,
         bool more_messages)
 {
diff --git a/src/core/system_parameters/rtcm.h b/src/core/system_parameters/rtcm.h
index 58bc6d498..1e9101d11 100644
--- a/src/core/system_parameters/rtcm.h
+++ b/src/core/system_parameters/rtcm.h
@@ -166,7 +166,6 @@ public:
             unsigned int clock_steering_indicator,
             unsigned int external_clock_indicator,
             int smooth_int,
-            bool sync_flag,
             bool divergence_free,
             bool more_messages);
 
@@ -182,7 +181,6 @@ public:
             unsigned int clock_steering_indicator,
             unsigned int external_clock_indicator,
             int smooth_int,
-            bool sync_flag,
             bool divergence_free,
             bool more_messages);
 
@@ -198,7 +196,6 @@ public:
             unsigned int clock_steering_indicator,
             unsigned int external_clock_indicator,
             int smooth_int,
-            bool sync_flag,
             bool divergence_free,
             bool more_messages);
 
@@ -214,7 +211,6 @@ public:
             unsigned int clock_steering_indicator,
             unsigned int external_clock_indicator,
             int smooth_int,
-            bool sync_flag,
             bool divergence_free,
             bool more_messages);
 
@@ -230,7 +226,6 @@ public:
             unsigned int clock_steering_indicator,
             unsigned int external_clock_indicator,
             int smooth_int,
-            bool sync_flag,
             bool divergence_free,
             bool more_messages);
 
@@ -246,7 +241,6 @@ public:
             unsigned int clock_steering_indicator,
             unsigned int external_clock_indicator,
             int smooth_int,
-            bool sync_flag,
             bool divergence_free,
             bool more_messages);
 
@@ -262,7 +256,6 @@ public:
             unsigned int clock_steering_indicator,
             unsigned int external_clock_indicator,
             int smooth_int,
-            bool sync_flag,
             bool divergence_free,
             bool more_messages);
 
diff --git a/src/tests/formats/rtcm_test.cc b/src/tests/formats/rtcm_test.cc
index 390e0fb85..3aaab417f 100644
--- a/src/tests/formats/rtcm_test.cc
+++ b/src/tests/formats/rtcm_test.cc
@@ -341,7 +341,6 @@ TEST(Rtcm_Test, MSMCell)
     unsigned int clock_steering_indicator = 0;
     unsigned int external_clock_indicator = 0;
     int smooth_int = 0;
-    bool sync_flag = false;
     bool divergence_free = false;
     bool more_messages = false;
     double obs_time = 25.0;
@@ -358,7 +357,6 @@ TEST(Rtcm_Test, MSMCell)
             clock_steering_indicator,
             external_clock_indicator,
             smooth_int,
-            sync_flag,
             divergence_free,
             more_messages);
 
@@ -384,7 +382,6 @@ TEST(Rtcm_Test, MSMCell)
              clock_steering_indicator,
              external_clock_indicator,
              smooth_int,
-             sync_flag,
              divergence_free,
              more_messages);
     std::string MSM1_bin_2 = rtcm->hex_to_bin(MSM1_2);
@@ -412,7 +409,6 @@ TEST(Rtcm_Test, MSMCell)
                 clock_steering_indicator,
                 external_clock_indicator,
                 smooth_int,
-                sync_flag,
                 divergence_free,
                 more_messages);
     std::string MSM1_bin_3 = rtcm->hex_to_bin(MSM1_3);
@@ -465,7 +461,6 @@ TEST(Rtcm_Test, MSM1)
     unsigned int clock_steering_indicator = 0;
     unsigned int external_clock_indicator = 0;
     int smooth_int = 0;
-    bool sync_flag = false;
     bool divergence_free = false;
     bool more_messages = false;
     double obs_time = 25.0;
@@ -480,7 +475,6 @@ TEST(Rtcm_Test, MSM1)
             clock_steering_indicator,
             external_clock_indicator,
             smooth_int,
-            sync_flag,
             divergence_free,
             more_messages);
 
@@ -528,7 +522,6 @@ TEST(Rtcm_Test, MSM1)
             clock_steering_indicator,
             external_clock_indicator,
             smooth_int,
-            sync_flag,
             divergence_free,
             more_messages);
     std::string MSM1_bin2 = rtcm->hex_to_bin(MSM1_2);