diff --git a/cmake/run_test_check_no_stderr.cmake b/cmake/run_test_check_no_stderr.cmake
new file mode 100644
index 00000000..660bd9bc
--- /dev/null
+++ b/cmake/run_test_check_no_stderr.cmake
@@ -0,0 +1,27 @@
+#
+# Test script to check that stderr does not contain a warning message
+#
+
+if(NOT cmd)
+    message(FATAL_ERROR "Variable 'cmd' not defined")
+endif()
+
+separate_arguments(cmd)
+
+execute_process(
+    COMMAND ${cmd}
+    RESULT_VARIABLE _return_code
+    OUTPUT_VARIABLE _stdout
+    ERROR_VARIABLE _stderr
+)
+
+if(NOT _return_code EQUAL 0)
+    message(FATAL_ERROR "Command failed with return code ${_return_code}")
+endif()
+
+string(FIND "${_stderr}" "WARNING:" _found_pos)
+if(NOT _found_pos EQUAL -1)
+    message(FATAL_ERROR "Unexpected warning message found in stderr output: '${_stderr}'")
+endif()
+
+message(STATUS "Test passed: No warning message found")
\ No newline at end of file
diff --git a/cmake/run_test_check_stderr.cmake b/cmake/run_test_check_stderr.cmake
new file mode 100644
index 00000000..4448b3ed
--- /dev/null
+++ b/cmake/run_test_check_stderr.cmake
@@ -0,0 +1,31 @@
+#
+# Test script to check that stderr contains the expected warning message
+#
+
+if(NOT cmd)
+    message(FATAL_ERROR "Variable 'cmd' not defined")
+endif()
+
+if(NOT expected_stderr)
+    message(FATAL_ERROR "Variable 'expected_stderr' not defined")
+endif()
+
+separate_arguments(cmd)
+
+execute_process(
+    COMMAND ${cmd}
+    RESULT_VARIABLE _return_code
+    OUTPUT_VARIABLE _stdout
+    ERROR_VARIABLE _stderr
+)
+
+if(NOT _return_code EQUAL 0)
+    message(FATAL_ERROR "Command failed with return code ${_return_code}")
+endif()
+
+string(FIND "${_stderr}" "${expected_stderr}" _found_pos)
+if(_found_pos EQUAL -1)
+    message(FATAL_ERROR "Expected stderr message '${expected_stderr}' not found in stderr output: '${_stderr}'")
+endif()
+
+message(STATUS "Test passed: Found expected stderr message")
\ No newline at end of file
diff --git a/src/cmd.cpp b/src/cmd.cpp
index 7e232565..9c82a7c4 100644
--- a/src/cmd.cpp
+++ b/src/cmd.cpp
@@ -23,6 +23,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #include "cmd.hpp"
 
 #include "exception.hpp"
+#include "util.hpp"
 
 #include <osmium/index/map.hpp>
 #include <osmium/osm/entity_bits.hpp>
@@ -177,3 +178,11 @@ std::string check_index_type(const std::string& index_type_name, bool allow_none
 
     return index_type_name;
 }
+
+void with_osm_output::warn_locations_on_ways_lost(const std::vector<osmium::io::File>& input_files, const Command& command) const {
+    if (command.should_warn_locations_lost() &&
+        has_locations_on_ways(input_files) &&
+        m_output_format.find("locations_on_ways") == std::string::npos) {
+        warning("Input file contains locations on ways that will be lost in output. Use --output-format with locations_on_ways option to preserve node locations on ways.");
+    }
+}
diff --git a/src/cmd.hpp b/src/cmd.hpp
index d2f574f1..59c2c749 100644
--- a/src/cmd.hpp
+++ b/src/cmd.hpp
@@ -118,6 +118,10 @@ class Command {
     void print_arguments(const std::string& command);
     void show_memory_used();
 
+    virtual bool should_warn_locations_lost() const {
+        return false;
+    }
+
     osmium::osm_entity_bits::type osm_entity_bits() const {
         return m_osm_entity_bits;
     }
@@ -262,6 +266,8 @@ class with_osm_output {
         return m_output_overwrite;
     }
 
+    void warn_locations_on_ways_lost(const std::vector<osmium::io::File>& input_files, const Command& command) const;
+
 }; // class with_osm_output
 
 
diff --git a/src/command_apply_changes.cpp b/src/command_apply_changes.cpp
index 22d712dc..2d7043e1 100644
--- a/src/command_apply_changes.cpp
+++ b/src/command_apply_changes.cpp
@@ -279,6 +279,8 @@ bool CommandApplyChanges::run() {
         m_output_file.set("locations_on_ways");
     }
 
+    warn_locations_on_ways_lost({m_input_file}, *this);
+
     m_vout << "Opening output file...\n";
     osmium::io::Writer writer{m_output_file, m_output_overwrite, m_fsync};
 
@@ -357,12 +359,20 @@ bool CommandApplyChanges::run() {
             const auto input = osmium::io::make_input_iterator_range<osmium::OSMObject>(reader);
             auto output_it = boost::make_function_output_iterator(copy_first_with_id(&writer));
 
+            // Suppress false positive GCC 15 warning with boost::make_function_output_iterator
+#if defined(__GNUC__) && (__GNUC__ >= 15)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#endif
             std::set_union(objects.begin(),
                            objects.end(),
                            input.begin(),
                            input.end(),
                            output_it,
                            osmium::object_order_type_id_reverse_version());
+#if defined(__GNUC__) && (__GNUC__ >= 15)
+#pragma GCC diagnostic pop
+#endif
         }
     }
 
diff --git a/src/command_apply_changes.hpp b/src/command_apply_changes.hpp
index af2a4e16..3c06afd8 100644
--- a/src/command_apply_changes.hpp
+++ b/src/command_apply_changes.hpp
@@ -67,6 +67,10 @@ class CommandApplyChanges : public CommandWithSingleOSMInput, public with_osm_ou
         return "osmium apply-changes [OPTIONS] OSM-FILE OSM-CHANGE-FILE...";
     }
 
+    bool should_warn_locations_lost() const override {
+        return true;
+    }
+
 }; // class CommandApplyChanges
 
 
diff --git a/src/command_cat.cpp b/src/command_cat.cpp
index a4d627e7..f6e84f9e 100644
--- a/src/command_cat.cpp
+++ b/src/command_cat.cpp
@@ -154,6 +154,8 @@ void report_filename(osmium::VerboseOutput* vout, const osmium::io::File& file,
 } // anonymous namespace
 
 bool CommandCat::run() {
+    warn_locations_on_ways_lost(m_input_files, *this);
+    
     std::size_t bytes_written = 0;
 
     if (m_input_files.size() == 1) { // single input file
diff --git a/src/command_cat.hpp b/src/command_cat.hpp
index 8532daf9..5bb9d393 100644
--- a/src/command_cat.hpp
+++ b/src/command_cat.hpp
@@ -61,6 +61,10 @@ class CommandCat : public CommandWithMultipleOSMInputs, public with_osm_output {
         return "osmium cat [OPTIONS] OSM-FILE...";
     }
 
+    bool should_warn_locations_lost() const override {
+        return true;
+    }
+
 }; // class CommandCat
 
 #endif // COMMAND_CAT_HPP
diff --git a/src/command_sort.cpp b/src/command_sort.cpp
index 8ff3dc49..bbe8ee5a 100644
--- a/src/command_sort.cpp
+++ b/src/command_sort.cpp
@@ -104,6 +104,8 @@ void CommandSort::show_arguments() {
 }
 
 bool CommandSort::run_single_pass() {
+    warn_locations_on_ways_lost(m_input_files, *this);
+    
     osmium::io::Writer writer{m_output_file, m_output_overwrite, m_fsync};
 
     std::vector<osmium::memory::Buffer> data;
@@ -170,6 +172,8 @@ bool CommandSort::run_single_pass() {
 }
 
 bool CommandSort::run_multi_pass() {
+    warn_locations_on_ways_lost(m_input_files, *this);
+    
     osmium::io::Writer writer{m_output_file, m_output_overwrite, m_fsync};
 
     osmium::Box bounding_box;
diff --git a/src/command_sort.hpp b/src/command_sort.hpp
index 8c2ad804..6ecb3d21 100644
--- a/src/command_sort.hpp
+++ b/src/command_sort.hpp
@@ -56,6 +56,10 @@ class CommandSort : public CommandWithMultipleOSMInputs, public with_osm_output
         return "osmium sort [OPTIONS] OSM-FILE...";
     }
 
+    bool should_warn_locations_lost() const override {
+        return true;
+    }
+
 }; // class CommandSort
 
 
diff --git a/src/util.cpp b/src/util.cpp
index 1a3468af..e7899ad3 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -25,6 +25,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #include "exception.hpp"
 
 #include <osmium/io/file.hpp>
+#include <osmium/io/reader.hpp>
 #include <osmium/osm/area.hpp>
 #include <osmium/tags/tags_filter.hpp>
 #include <osmium/util/file.hpp>
@@ -276,3 +277,23 @@ double show_gbytes(std::size_t value) noexcept {
     return static_cast<double>(show_mbytes(value)) / 1000; // NOLINT(bugprone-integer-division)
 }
 
+bool has_locations_on_ways(const std::vector<osmium::io::File>& input_files) {
+    for (const auto& file : input_files) {
+        try {
+            osmium::io::Reader reader{file, osmium::osm_entity_bits::nothing};
+            const osmium::io::Header& header = reader.header();
+
+            for (const auto& option : header) {
+                if (option.first.find("pbf_optional_feature") != std::string::npos && 
+                    option.second == "LocationsOnWays") {
+                    return true;
+                }
+            }
+        } catch (...) {
+            // Ignore files that can't be opened for header check
+            continue;
+        }
+    }
+    return false;
+}
+
diff --git a/src/util.hpp b/src/util.hpp
index 13c6140a..8bd9512b 100644
--- a/src/util.hpp
+++ b/src/util.hpp
@@ -53,5 +53,6 @@ const char* object_type_as_string(const osmium::OSMObject& object) noexcept;
 bool ends_with(const std::string& str, const std::string& suffix);
 std::size_t show_mbytes(std::size_t value) noexcept;
 double show_gbytes(std::size_t value) noexcept;
+bool has_locations_on_ways(const std::vector<osmium::io::File>& input_files);
 
 #endif // UTIL_HPP
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index f3eb779f..c6aba05d 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -99,7 +99,7 @@ foreach(_cmd IN LISTS OSMIUM_COMMANDS)
     endif()
 endforeach()
 
-foreach(_extra_tests formats help misc)
+foreach(_extra_tests formats help locations-on-ways misc)
     message(STATUS "Adding tests in ${_extra_tests}")
     add_subdirectory(${_extra_tests})
 endforeach()
diff --git a/test/locations-on-ways/CMakeLists.txt b/test/locations-on-ways/CMakeLists.txt
new file mode 100644
index 00000000..bd368656
--- /dev/null
+++ b/test/locations-on-ways/CMakeLists.txt
@@ -0,0 +1,90 @@
+#
+# Test LocationsOnWays warning functionality across multiple commands
+#
+
+function(check_warning_cat _name _format _expected_stderr)
+    set(_input_paths "")
+    foreach(_file ${ARGN})
+        set(_input_paths "${_input_paths} ${CMAKE_SOURCE_DIR}/test/locations-on-ways/${_file}")
+    endforeach()
+    set(_cmd "$<TARGET_FILE:osmium> cat --no-progress --generator=test${_input_paths} -f ${_format} -o ${CMAKE_BINARY_DIR}/test/locations-on-ways/warning-cat-${_name}.osm --overwrite")
+    add_test(
+        NAME "locations-on-ways-cat-${_name}"
+        COMMAND ${CMAKE_COMMAND}
+        -D cmd:FILEPATH=${_cmd}
+        -D expected_stderr:STRING=${_expected_stderr}
+        -P ${CMAKE_SOURCE_DIR}/cmake/run_test_check_stderr.cmake
+    )
+endfunction()
+
+function(check_no_warning_cat _name _format)
+    set(_input_paths "")
+    foreach(_file ${ARGN})
+        set(_input_paths "${_input_paths} ${CMAKE_SOURCE_DIR}/test/locations-on-ways/${_file}")
+    endforeach()
+    set(_cmd "$<TARGET_FILE:osmium> cat --no-progress --generator=test${_input_paths} -f ${_format} -o ${CMAKE_BINARY_DIR}/test/locations-on-ways/no-warning-cat-${_name}.osm --overwrite")
+    add_test(
+        NAME "locations-on-ways-cat-${_name}"
+        COMMAND ${CMAKE_COMMAND}
+        -D cmd:FILEPATH=${_cmd}
+        -P ${CMAKE_SOURCE_DIR}/cmake/run_test_check_no_stderr.cmake
+    )
+endfunction()
+
+function(check_warning_sort _name _format _expected_stderr)
+    set(_input_paths "")
+    foreach(_file ${ARGN})
+        set(_input_paths "${_input_paths} ${CMAKE_SOURCE_DIR}/test/locations-on-ways/${_file}")
+    endforeach()
+    set(_cmd "$<TARGET_FILE:osmium> sort --no-progress --generator=test${_input_paths} -f ${_format} -o ${CMAKE_BINARY_DIR}/test/locations-on-ways/warning-sort-${_name}.osm --overwrite")
+    add_test(
+        NAME "locations-on-ways-sort-${_name}"
+        COMMAND ${CMAKE_COMMAND}
+        -D cmd:FILEPATH=${_cmd}
+        -D expected_stderr:STRING=${_expected_stderr}
+        -P ${CMAKE_SOURCE_DIR}/cmake/run_test_check_stderr.cmake
+    )
+    set(_cmd_mp "$<TARGET_FILE:osmium> sort --no-progress --generator=test -s multipass${_input_paths} -f ${_format} -o ${CMAKE_BINARY_DIR}/test/locations-on-ways/warning-sort-${_name}_mp.osm --overwrite")
+    add_test(
+        NAME "locations-on-ways-sort-${_name}_mp"
+        COMMAND ${CMAKE_COMMAND}
+        -D cmd:FILEPATH=${_cmd_mp}
+        -D expected_stderr:STRING=${_expected_stderr}
+        -P ${CMAKE_SOURCE_DIR}/cmake/run_test_check_stderr.cmake
+    )
+endfunction()
+
+function(check_no_warning_sort _name _format)
+    set(_input_paths "")
+    foreach(_file ${ARGN})
+        set(_input_paths "${_input_paths} ${CMAKE_SOURCE_DIR}/test/locations-on-ways/${_file}")
+    endforeach()
+    set(_cmd "$<TARGET_FILE:osmium> sort --no-progress --generator=test${_input_paths} -f ${_format} -o ${CMAKE_BINARY_DIR}/test/locations-on-ways/no-warning-sort-${_name}.osm --overwrite")
+    add_test(
+        NAME "locations-on-ways-sort-${_name}"
+        COMMAND ${CMAKE_COMMAND}
+        -D cmd:FILEPATH=${_cmd}
+        -P ${CMAKE_SOURCE_DIR}/cmake/run_test_check_no_stderr.cmake
+    )
+    set(_cmd_mp "$<TARGET_FILE:osmium> sort --no-progress --generator=test -s multipass${_input_paths} -f ${_format} -o ${CMAKE_BINARY_DIR}/test/locations-on-ways/no-warning-sort-${_name}_mp.osm --overwrite")
+    add_test(
+        NAME "locations-on-ways-sort-${_name}_mp"
+        COMMAND ${CMAKE_COMMAND}
+        -D cmd:FILEPATH=${_cmd_mp}
+        -P ${CMAKE_SOURCE_DIR}/cmake/run_test_check_no_stderr.cmake
+    )
+endfunction()
+
+#-----------------------------------------------------------------------------
+
+# Test cases with files that HAVE locations on ways - should warn when output format doesn't preserve them
+# Uses multiple files where one has locations on ways
+check_warning_cat(warning-pbf-to-xml xml "WARNING: Input file contains locations on ways that will be lost in output." input-with-locations.osm.pbf input-without-locations.osm.pbf)
+check_warning_sort(warning-pbf-to-xml xml "WARNING: Input file contains locations on ways that will be lost in output." input-with-locations.osm.pbf input-without-locations.osm.pbf)
+
+# Test cases with files that DON'T have locations on ways - should NOT warn
+# Uses multiple files where none have locations on ways
+check_no_warning_cat(no-warning-pbf-to-xml xml input-without-locations.osm.pbf input-without-locations.osm.pbf)
+check_no_warning_sort(no-warning-pbf-to-xml xml input-without-locations.osm.pbf input-without-locations.osm.pbf)
+
+#-----------------------------------------------------------------------------
\ No newline at end of file
diff --git a/test/locations-on-ways/input-with-locations.osm.pbf b/test/locations-on-ways/input-with-locations.osm.pbf
new file mode 100644
index 00000000..ffc72ac1
Binary files /dev/null and b/test/locations-on-ways/input-with-locations.osm.pbf differ
diff --git a/test/locations-on-ways/input-without-locations.osm.pbf b/test/locations-on-ways/input-without-locations.osm.pbf
new file mode 100644
index 00000000..5884b660
Binary files /dev/null and b/test/locations-on-ways/input-without-locations.osm.pbf differ