diff --git a/src/algorithms/signal_generator/gnuradio_blocks/signal_generator_c.cc b/src/algorithms/signal_generator/gnuradio_blocks/signal_generator_c.cc
index 218ce87ab..b67404563 100644
--- a/src/algorithms/signal_generator/gnuradio_blocks/signal_generator_c.cc
+++ b/src/algorithms/signal_generator/gnuradio_blocks/signal_generator_c.cc
@@ -429,7 +429,7 @@ int signal_generator_c::general_work(int noutput_items __attribute__((unused)),
                                     // New random data bit
                                     current_data_bit_int_[sat] = (uniform_dist(e1) % 2) == 0 ? 1 : -1;
                                 }
-                            data_modulation_[sat] = current_data_bit_int_[sat] * (GALILEO_E5B_I_SECONDARY_CODE[((ms_counter_[sat] + delay_sec_[sat]) % 20)] == '0' ? 1 : -1);
+                            data_modulation_[sat] = current_data_bit_int_[sat] * (GALILEO_E5B_I_SECONDARY_CODE[((ms_counter_[sat] + delay_sec_[sat]) % 4)] == '0' ? 1 : -1);
                             pilot_modulation_[sat] = (GALILEO_E5B_Q_SECONDARY_CODE[PRN_[sat] - 1][((ms_counter_[sat] + delay_sec_[sat]) % 100)] == '0' ? 1 : -1);
 
                             ms_counter_[sat] = ms_counter_[sat] + static_cast<int>(round(1e3 * GALILEO_E5B_CODE_PERIOD_S));