diff --git a/cmake/QtBuildRepoExamplesHelpers.cmake b/cmake/QtBuildRepoExamplesHelpers.cmake
index 13e6822da2d..4c60bdd79e3 100644
--- a/cmake/QtBuildRepoExamplesHelpers.cmake
+++ b/cmake/QtBuildRepoExamplesHelpers.cmake
@@ -135,6 +135,13 @@ endmacro()
 # Allows building an example either as an ExternalProject or in-tree with the Qt build.
 # Also allows installing the example sources.
 function(qt_internal_add_example subdir)
+    # Don't show warnings for examples that were added via qt_internal_add_example.
+    # Those that are added via add_subdirectory will see the warning, due to the parent scope
+    # having the variable set to TRUE.
+    if(QT_FEATURE_developer_build AND NOT QT_NO_WARN_ABOUT_EXAMPLE_ADD_SUBDIRECTORY_WARNING)
+        set(QT_WARN_ABOUT_EXAMPLE_ADD_SUBDIRECTORY FALSE)
+    endif()
+
     # Pre-compute unique example name based on the subdir, in case of target name clashes.
     qt_internal_get_example_unique_name(unique_example_name "${subdir}")
 
diff --git a/cmake/QtBuildRepoHelpers.cmake b/cmake/QtBuildRepoHelpers.cmake
index bcee2b5a871..f2d25e03130 100644
--- a/cmake/QtBuildRepoHelpers.cmake
+++ b/cmake/QtBuildRepoHelpers.cmake
@@ -447,7 +447,15 @@ macro(qt_build_repo_impl_examples)
         message(STATUS "Configuring examples.")
 
         option(QT_BUILD_EXAMPLES_PROJECT_${PROJECT_NAME} "Configure examples for project ${PROJECT_NAME}" TRUE)
-        if (QT_BUILD_EXAMPLES_PROJECT_${PROJECT_NAME})
+        if(QT_BUILD_EXAMPLES_PROJECT_${PROJECT_NAME})
+
+            # Set this before any examples subdirectories are added, to warn about examples that are
+            # added via add_subdirectory() calls instead of qt_internal_add_example().
+            if(QT_FEATURE_developer_build
+                    AND NOT QT_NO_WARN_ABOUT_EXAMPLE_ADD_SUBDIRECTORY_WARNING)
+                set(QT_WARN_ABOUT_EXAMPLE_ADD_SUBDIRECTORY TRUE)
+            endif()
+
             add_subdirectory(examples)
         endif()
     endif()
diff --git a/cmake/QtPublicTargetHelpers.cmake b/cmake/QtPublicTargetHelpers.cmake
index df9e87db117..02d55465608 100644
--- a/cmake/QtPublicTargetHelpers.cmake
+++ b/cmake/QtPublicTargetHelpers.cmake
@@ -321,3 +321,17 @@ function(_qt_internal_set_up_static_runtime_library target)
         endif()
     endif()
 endfunction()
+
+function(_qt_internal_warn_about_example_add_subdirectory)
+    # This is set by qt_build_repo_impl_examples() in QtBuildRepoHelpers.cmake, only for developer
+    # builds, to catch examples that are added via add_subdirectory instead of via
+    # qt_internal_add_example.
+    if(QT_WARN_ABOUT_EXAMPLE_ADD_SUBDIRECTORY)
+        get_filename_component(dir_name "${PROJECT_SOURCE_DIR}" NAME)
+        message(AUTHOR_WARNING
+            "It looks like this example project was added via add_subdirectory instead of via "
+            "qt_internal_add_example. This causes issues in certain build configurations. Please "
+            "change the code to use\n  qt_internal_add_example(${dir_name})\ninstead."
+        )
+    endif()
+endfunction()
diff --git a/src/corelib/Qt6CoreMacros.cmake b/src/corelib/Qt6CoreMacros.cmake
index f8fda0ab833..07289156a3a 100644
--- a/src/corelib/Qt6CoreMacros.cmake
+++ b/src/corelib/Qt6CoreMacros.cmake
@@ -617,6 +617,8 @@ set(_Qt6_COMPONENT_PATH "${CMAKE_CURRENT_LIST_DIR}/..")
 function(qt6_add_executable target)
     cmake_parse_arguments(PARSE_ARGV 1 arg "MANUAL_FINALIZATION" "" "")
 
+    _qt_internal_warn_about_example_add_subdirectory()
+
     _qt_internal_create_executable("${target}" ${arg_UNPARSED_ARGUMENTS})
     target_link_libraries("${target}" PRIVATE Qt6::Core)
     set_property(TARGET ${target} PROPERTY _qt_expects_finalization TRUE)