diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7461e130f..b86bec12a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -327,7 +327,7 @@ set(GNSSSDR_GLOG_LOCAL_VERSION "0.4.0")
 set(GNSSSDR_ARMADILLO_LOCAL_VERSION "10.1.x")
 set(GNSSSDR_GTEST_LOCAL_VERSION "1.10.0")
 set(GNSSSDR_GNSS_SIM_LOCAL_VERSION "master")
-set(GNSSSDR_GPSTK_LOCAL_VERSION "3.0.0")
+set(GNSSSDR_GPSTK_LOCAL_VERSION "8.0.0")
 set(GNSSSDR_MATIO_LOCAL_VERSION "1.5.18")
 set(GNSSSDR_PUGIXML_LOCAL_VERSION "1.11")
 set(GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION "3.14.0")
@@ -601,10 +601,16 @@ endif()
 # Detect availability of std::filesystem and set C++ standard accordingly
 ################################################################################
 set(FILESYSTEM_FOUND FALSE)
+if(NOT ENABLE_OWN_GPSTK)
+    find_package(GPSTK)
+    set_package_properties(GPSTK PROPERTIES
+        PURPOSE "Used in some Extra Tests."
+    )
+endif()
 if(NOT (GNURADIO_VERSION VERSION_LESS 3.8) AND LOG4CPP_READY_FOR_CXX17)
     # Check if we have std::filesystem
     if(NOT (CMAKE_VERSION VERSION_LESS 3.8))
-        if(NOT (ENABLE_UNIT_TESTING_EXTRA OR ENABLE_SYSTEM_TESTING_EXTRA OR ENABLE_FPGA))  # Fix for GPTSk
+        if(NOT GPSTK_FOUND OR NOT (GPSTK_FOUND AND GPSTK_OLDER_THAN_8))  # Fix for GPSTk < 8.0.0
             find_package(FILESYSTEM COMPONENTS Final Experimental)
             set_package_properties(FILESYSTEM PROPERTIES
                 URL "https://en.cppreference.com/w/cpp/filesystem"
@@ -613,7 +619,7 @@ if(NOT (GNURADIO_VERSION VERSION_LESS 3.8) AND LOG4CPP_READY_FOR_CXX17)
                 TYPE OPTIONAL
             )
         endif()
-        if(${FILESYSTEM_FOUND})
+        if(FILESYSTEM_FOUND)
             if(CMAKE_VERSION VERSION_LESS 3.13)
                 set(CMAKE_CXX_STANDARD 17)
             else()
diff --git a/cmake/Modules/FindGPSTK.cmake b/cmake/Modules/FindGPSTK.cmake
index 3544da554..102540f21 100644
--- a/cmake/Modules/FindGPSTK.cmake
+++ b/cmake/Modules/FindGPSTK.cmake
@@ -80,6 +80,10 @@ else()
     )
 endif()
 
+if(GPSTK_FOUND AND NOT EXISTS ${GPSTK_INCLUDE_DIR}/gpstk/SatelliteSystem.hpp)
+    set(GPSTK_OLDER_THAN_8 TRUE)
+endif()
+
 set_package_properties(GPSTK PROPERTIES
     URL "https://github.com/SGL-UT/GPSTk"
 )
diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index e55757931..7786cca35 100644
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -322,11 +322,6 @@ if(ENABLE_UNIT_TESTING_EXTRA OR ENABLE_SYSTEM_TESTING_EXTRA OR ENABLE_FPGA)
     ############################################################################
     # Local installation of GPSTk https://github.com/SGL-UT/GPSTk
     ############################################################################
-    find_package(GPSTK)
-    set_package_properties(GPSTK PROPERTIES
-        PURPOSE "Used in some Extra Tests."
-        TYPE REQUIRED
-    )
     if(NOT GPSTK_FOUND OR ENABLE_OWN_GPSTK)
         set_package_properties(GPSTK PROPERTIES
             PURPOSE "GPSTk v${GNSSSDR_GPSTK_LOCAL_VERSION} will be automatically downloaded and built when doing '${CMAKE_MAKE_PROGRAM_PRETTY_NAME}'."
@@ -348,7 +343,7 @@ if(ENABLE_UNIT_TESTING_EXTRA OR ENABLE_SYSTEM_TESTING_EXTRA OR ENABLE_FPGA)
                 SOURCE_DIR ${CMAKE_BINARY_DIR}/thirdparty/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}
                 BINARY_DIR ${CMAKE_BINARY_DIR}/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}
                 PATCH_COMMAND cd ${CMAKE_BINARY_DIR}/thirdparty/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION} && ${Patch_EXECUTABLE} ${CMAKE_BINARY_DIR}/thirdparty/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}/CMakeLists.txt < ${CMAKE_SOURCE_DIR}/src/tests/data/gpstk_static.patch
-                CMAKE_ARGS ${GTEST_COMPILER} ${TOOLCHAIN_ARG} -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}/install -DBUILD_EXT=OFF -DBUILD_PYTHON=OFF -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} -DCMAKE_CXX_STANDARD=11 -DCMAKE_CXX_EXTENSIONS=ON -DCMAKE_C_STANDARD=11 -DCMAKE_C_EXTENSIONS=ON
+                CMAKE_ARGS ${GTEST_COMPILER} ${TOOLCHAIN_ARG} -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}/install -DBUILD_EXT=ON -DBUILD_PYTHON=OFF -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} -DCMAKE_CXX_STANDARD=11 -DCMAKE_CXX_EXTENSIONS=ON -DCMAKE_C_STANDARD=11 -DCMAKE_C_EXTENSIONS=ON
                 BUILD_COMMAND ${GPSTK_BUILD_COMMAND}
                 UPDATE_COMMAND ""
                 PATCH_COMMAND ""
@@ -368,7 +363,7 @@ if(ENABLE_UNIT_TESTING_EXTRA OR ENABLE_SYSTEM_TESTING_EXTRA OR ENABLE_FPGA)
                 SOURCE_DIR ${CMAKE_BINARY_DIR}/thirdparty/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}
                 BINARY_DIR ${CMAKE_BINARY_DIR}/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}
                 PATCH_COMMAND cd ${CMAKE_BINARY_DIR}/thirdparty/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION} && ${Patch_EXECUTABLE} ${CMAKE_BINARY_DIR}/thirdparty/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}/CMakeLists.txt < ${CMAKE_SOURCE_DIR}/src/tests/data/gpstk_static.patch
-                CMAKE_ARGS ${GTEST_COMPILER} ${TOOLCHAIN_ARG} -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}/install -DBUILD_EXT=OFF -DBUILD_PYTHON=OFF -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} -DCMAKE_CXX_STANDARD=14 -DCMAKE_CXX_EXTENSIONS=ON -DCMAKE_C_STANDARD=11 -DCMAKE_C_EXTENSIONS=ON
+                CMAKE_ARGS ${GTEST_COMPILER} ${TOOLCHAIN_ARG} -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}/install -DBUILD_EXT=ON -DBUILD_PYTHON=OFF -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} -DCMAKE_CXX_STANDARD=14 -DCMAKE_CXX_EXTENSIONS=ON -DCMAKE_C_STANDARD=11 -DCMAKE_C_EXTENSIONS=ON
                 BUILD_COMMAND ${GPSTK_BUILD_COMMAND} ${GPSTK_PARALLEL_BUILD}
                 BUILD_BYPRODUCTS ${CMAKE_BINARY_DIR}/gpstk-${GNSSSDR_GPSTK_LOCAL_VERSION}/install/${CMAKE_INSTALL_LIBDIR}/${CMAKE_FIND_LIBRARY_PREFIXES}gpstk${CMAKE_STATIC_LIBRARY_SUFFIX}
                 UPDATE_COMMAND ""
@@ -526,6 +521,9 @@ if(ENABLE_UNIT_TESTING)
     endif()
     if(ENABLE_UNIT_TESTING_EXTRA)
         target_link_libraries(run_tests PRIVATE Gpstk::gpstk)
+        if(GPSTK_OLDER_THAN_8)
+	        target_compile_definitions(run_tests PRIVATE -DOLD_GPSTK=1)
+        endif()
     endif()
     if(ENABLE_STRIP)
         set_target_properties(run_tests PROPERTIES LINK_FLAGS "-s")
diff --git a/src/tests/data/gpstk_static.patch b/src/tests/data/gpstk_static.patch
index 531bb76fc..c8ed6de56 100644
--- a/src/tests/data/gpstk_static.patch
+++ b/src/tests/data/gpstk_static.patch
@@ -2,7 +2,7 @@ SPDX-License-Identifier: GPL-3.0-or-later
 SPDX-FileCopyrightText: 2020 Carles Fernandez-Prades <carles.fernandez@cttc.es>
 --- CMakeLists.txt	2020-10-25 10:06:26.000000000 +0100
 +++ CMakeLists.txt	2020-10-25 10:06:11.000000000 +0100
-@@ -74,7 +74,16 @@
+@@ -77,7 +77,16 @@
  
  
  include( BuildSetup.cmake )
diff --git a/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test.cc b/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test.cc
index 9aad51054..7db35bcb0 100644
--- a/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test.cc
+++ b/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test.cc
@@ -1577,13 +1577,25 @@ bool HybridObservablesTest::ReadRinexObs(std::vector<arma::mat>* obs_vec, Gnss_S
                             switch (gnss.System)
                                 {
                                 case 'G':
+#if OLD_GPSTK
                                     prn = gpstk::SatID(myprn, gpstk::SatID::systemGPS);
+#else
+                                    prn = gpstk::SatID(myprn, gpstk::SatelliteSystem::GPS);
+#endif
                                     break;
                                 case 'E':
+#if OLD_GPSTK
                                     prn = gpstk::SatID(myprn, gpstk::SatID::systemGalileo);
+#else
+                                    prn = gpstk::SatID(myprn, gpstk::SatelliteSystem::Galileo);
+#endif
                                     break;
                                 default:
+#if OLD_GPSTK
                                     prn = gpstk::SatID(myprn, gpstk::SatID::systemGPS);
+#else
+                                    prn = gpstk::SatID(myprn, gpstk::SatelliteSystem::GPS);
+#endif
                                 }
 
                             gpstk::CommonTime time = r_ref_data.time;
@@ -1741,7 +1753,7 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
                 {
                     // based on true observables metadata (for custom sdr generator)
                     // open true observables log file written by the simulator or based on provided RINEX obs
-                    std::vector<std::shared_ptr<Tracking_True_Obs_Reader>> true_reader_vec;
+                    std::vector<std::shared_ptr<Tracking_True_Obs_Reader> > true_reader_vec;
                     // read true data from the generator logs
                     true_reader_vec.push_back(std::make_shared<Tracking_True_Obs_Reader>());
                     std::cout << "Loading true observable data for PRN " << n.PRN << '\n';
@@ -1782,8 +1794,8 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
                 }
         }
 
-    std::vector<std::shared_ptr<TrackingInterface>> tracking_ch_vec;
-    std::vector<std::shared_ptr<TelemetryDecoderInterface>> tlm_ch_vec;
+    std::vector<std::shared_ptr<TrackingInterface> > tracking_ch_vec;
+    std::vector<std::shared_ptr<TelemetryDecoderInterface> > tlm_ch_vec;
 
     std::vector<gr::blocks::null_sink::sptr> null_sink_vec;
     for (unsigned int n = 0; n < gnss_synchro_vec.size(); n++)
diff --git a/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test_fpga.cc b/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test_fpga.cc
index e293023b4..833305e1e 100644
--- a/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test_fpga.cc
+++ b/src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test_fpga.cc
@@ -1668,13 +1668,25 @@ bool HybridObservablesTestFpga::ReadRinexObs(std::vector<arma::mat>* obs_vec, Gn
                             switch (gnss.System)
                                 {
                                 case 'G':
+#if OLD_GPSTK
                                     prn = gpstk::SatID(myprn, gpstk::SatID::systemGPS);
+#else
+                                    prn = gpstk::SatID(myprn, gpstk::SatelliteSystem::GPS);
+#endif
                                     break;
                                 case 'E':
+#if OLD_GPSTK
                                     prn = gpstk::SatID(myprn, gpstk::SatID::systemGalileo);
+#else
+                                    prn = gpstk::SatID(myprn, gpstk::SatelliteSystem::Galileo);
+#endif
                                     break;
                                 default:
+#if OLD_GPSTK
                                     prn = gpstk::SatID(myprn, gpstk::SatID::systemGPS);
+#else
+                                    prn = gpstk::SatID(myprn, gpstk::SatelliteSystem::GPS);
+#endif
                                 }
 
                             gpstk::CommonTime time = r_ref_data.time;
diff --git a/src/utils/rinex-tools/CMakeLists.txt b/src/utils/rinex-tools/CMakeLists.txt
index 5f907ecd8..569c48732 100644
--- a/src/utils/rinex-tools/CMakeLists.txt
+++ b/src/utils/rinex-tools/CMakeLists.txt
@@ -72,6 +72,10 @@ if("${ARMADILLO_VERSION_STRING}" VERSION_GREATER "9.800" OR (NOT ARMADILLO_FOUND
             ${GPSTK_INCLUDE_DIR}
     )
 
+    if(GPSTK_OLDER_THAN_8)
+        target_compile_definitions(obsdiff PUBLIC -DOLD_GPSTK=1)
+    endif()
+
     if(ENABLE_STRIP)
         set_target_properties(obsdiff PROPERTIES LINK_FLAGS "-s")
     endif()
diff --git a/src/utils/rinex-tools/obsdiff.cc b/src/utils/rinex-tools/obsdiff.cc
index 325c09972..7d892cb31 100644
--- a/src/utils/rinex-tools/obsdiff.cc
+++ b/src/utils/rinex-tools/obsdiff.cc
@@ -113,15 +113,27 @@ std::map<int, arma::mat> ReadRinexObs(const std::string& rinex_file, char system
             switch (system)
                 {
                 case 'G':
+#if OLD_GPSTK
                     prn.system = gpstk::SatID::systemGPS;
+#else
+                    prn.system = gpstk::SatelliteSystem::GPS;
+#endif
                     PRN_set = available_gps_prn;
                     break;
                 case 'E':
+#if OLD_GPSTK
                     prn.system = gpstk::SatID::systemGalileo;
+#else
+                    prn.system = gpstk::SatelliteSystem::Galileo;
+#endif
                     PRN_set = available_galileo_prn;
                     break;
                 default:
+#if OLD_GPSTK
                     prn.system = gpstk::SatID::systemGPS;
+#else
+                    prn.system = gpstk::SatelliteSystem::GPS;
+#endif
                     PRN_set = available_gps_prn;
                 }
 
@@ -1241,12 +1253,19 @@ double compute_rx_clock_error(const std::string& rinex_nav_filename, const std::
                             // pointer to the tropospheric model to be applied
                             try
                                 {
+#if OLD_GPSTK
                                     std::vector<gpstk::SatID::SatelliteSystem> Syss;
+#endif
                                     gpstk::Matrix<double> invMC;
                                     int iret;
-                                    // Call RAIMCompute.
+                                    // Call RAIMCompute
+#if OLD_GPSTK
                                     iret = raimSolver.RAIMCompute(rod.time, prnVec, Syss, rangeVec, invMC,
                                         &bcestore, tropModelPtr);
+#else
+                                    iret = raimSolver.RAIMCompute(rod.time, prnVec, rangeVec, invMC,
+                                        &bcestore, tropModelPtr);
+#endif
                                     switch (iret)
                                         {
                                         /// @return Return values: