diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 1739ca603..faca40e87 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -14,6 +14,16 @@ All notable changes to GNSS-SDR will be documented in this file.
 
 ## [Unreleased](https://github.com/gnss-sdr/gnss-sdr/tree/next)
 
+### Improvements in Availability:
+
+- Fixed the GPS L5 I5 and Q5 local code replicas. The XB sequence was wrapped
+  modulo the 10230-chip code length instead of its natural 8191-chip period
+  (IS-GPS-705J, Section 3.3.2.2), so the last chips of every code (as many as
+  its XB code advance) were taken from the wrong XB phase. Depending on the PRN,
+  this cost between 0.2 and 13.5 dB (about 5 dB on average) of correlation gain
+  in acquisition and tracking, also in FPGA-offloaded receivers. Reported by
+  @ObvMamut.
+
 ### Improvements in Efficiency:
 
 - Improved Signal Conditioner scheduling with portable, configuration-aware
diff --git a/src/algorithms/libs/gps_l5_signal_replica.cc b/src/algorithms/libs/gps_l5_signal_replica.cc
index ee5a14bac..2d2212d77 100644
--- a/src/algorithms/libs/gps_l5_signal_replica.cc
+++ b/src/algorithms/libs/gps_l5_signal_replica.cc
@@ -78,9 +78,9 @@ std::deque<bool> make_l5i_xa()
 std::deque<bool> make_l5i_xb()
 {
     std::deque<bool> xb = {true, true, true, true, true, true, true, true, true, true, true, true, true};
-    std::deque<bool> y(GPS_L5I_CODE_LENGTH_CHIPS, false);
+    std::deque<bool> y(GPS_L5_XB_CODE_LENGTH_CHIPS, false);
 
-    for (int32_t i = 0; i < GPS_L5I_CODE_LENGTH_CHIPS; i++)
+    for (int32_t i = 0; i < GPS_L5_XB_CODE_LENGTH_CHIPS; i++)
         {
             y[i] = xb[12];
             xb = l5i_xb_shift(xb);
@@ -106,9 +106,9 @@ std::deque<bool> make_l5q_xa()
 std::deque<bool> make_l5q_xb()
 {
     std::deque<bool> xb = {true, true, true, true, true, true, true, true, true, true, true, true, true};
-    std::deque<bool> y(GPS_L5Q_CODE_LENGTH_CHIPS, false);
+    std::deque<bool> y(GPS_L5_XB_CODE_LENGTH_CHIPS, false);
 
-    for (int32_t i = 0; i < GPS_L5Q_CODE_LENGTH_CHIPS; i++)
+    for (int32_t i = 0; i < GPS_L5_XB_CODE_LENGTH_CHIPS; i++)
         {
             y[i] = xb[12];
             xb = l5q_xb_shift(xb);
@@ -127,7 +127,7 @@ void make_l5i(own::span<int32_t> dest, int32_t prn)
 
     for (int32_t n = 0; n < GPS_L5I_CODE_LENGTH_CHIPS; n++)
         {
-            xb_shift[n] = xb[(xb_offset + n) % GPS_L5I_CODE_LENGTH_CHIPS];
+            xb_shift[n] = xb[(xb_offset + n) % GPS_L5_XB_CODE_LENGTH_CHIPS];
         }
 
     for (int32_t n = 0; n < GPS_L5I_CODE_LENGTH_CHIPS; n++)
@@ -147,7 +147,7 @@ void make_l5q(own::span<int32_t> dest, int32_t prn)
 
     for (int32_t n = 0; n < GPS_L5Q_CODE_LENGTH_CHIPS; n++)
         {
-            xb_shift[n] = xb[(xb_offset + n) % GPS_L5Q_CODE_LENGTH_CHIPS];
+            xb_shift[n] = xb[(xb_offset + n) % GPS_L5_XB_CODE_LENGTH_CHIPS];
         }
 
     for (int32_t n = 0; n < GPS_L5Q_CODE_LENGTH_CHIPS; n++)
diff --git a/src/core/system_parameters/GPS_L5.h b/src/core/system_parameters/GPS_L5.h
index 0d7cbb6df..d680e90d8 100644
--- a/src/core/system_parameters/GPS_L5.h
+++ b/src/core/system_parameters/GPS_L5.h
@@ -168,6 +168,7 @@ constexpr int32_t GPS_L5I_NH_CODE_LENGTH = 10;
 constexpr int32_t GPS_L5I_NH_CODE[10] = {0, 0, 0, 0, 1, 1, 0, 1, 0, 1};
 constexpr int32_t GPS_L5Q_NH_CODE_LENGTH = 20;
 constexpr int32_t GPS_L5Q_NH_CODE[20] = {0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0};
+constexpr int32_t GPS_L5_XB_CODE_LENGTH_CHIPS = 8191;
 constexpr char GPS_L5I_NH_CODE_STR[11] = "0000110101";
 constexpr char GPS_L5Q_NH_CODE_STR[21] = "00000100110101001110";