diff --git a/cmake/QtConfig.cmake.in b/cmake/QtConfig.cmake.in
index e6810e71f3a..d1ffc7456b9 100644
--- a/cmake/QtConfig.cmake.in
+++ b/cmake/QtConfig.cmake.in
@@ -150,7 +150,7 @@ foreach(module ${__qt_umbrella_find_components})
         # But don't match QtShaderTools and QtTools which are cross-compiled target package names.
         # Allow opt out just in case.
         get_filename_component(__qt_find_package_host_qt_path
-            "${Qt@PROJECT_VERSION_MAJOR@HostInfo_DIR}/.." ABSOLUTE)
+            "${@INSTALL_CMAKE_NAMESPACE@HostInfo_DIR}/.." ABSOLUTE)
         set(__qt_backup_cmake_prefix_path "${CMAKE_PREFIX_PATH}")
         set(__qt_backup_cmake_find_root_path "${CMAKE_FIND_ROOT_PATH}")
         list(PREPEND CMAKE_PREFIX_PATH "${__qt_find_package_host_qt_path}"
diff --git a/cmake/QtPostProcessHelpers.cmake b/cmake/QtPostProcessHelpers.cmake
index d57f68f09a4..180c207c7a2 100644
--- a/cmake/QtPostProcessHelpers.cmake
+++ b/cmake/QtPostProcessHelpers.cmake
@@ -432,7 +432,7 @@ endif()")
         # to the target CMAKE_INSTALL_DIR, if at all possible to do so in a reliable way.
         get_filename_component(qt_host_path_absolute "${QT_HOST_PATH}" ABSOLUTE)
         get_filename_component(qt_host_path_cmake_dir_absolute
-            "${Qt${PROJECT_VERSION_MAJOR}HostInfo_DIR}/.." ABSOLUTE)
+            "${${INSTALL_CMAKE_NAMESPACE}HostInfo_DIR}/.." ABSOLUTE)
     endif()
 
     if(third_party_deps OR platform_requires_host_info_package)
diff --git a/cmake/QtToolHelpers.cmake b/cmake/QtToolHelpers.cmake
index 22e083b1208..a7e1842c04f 100644
--- a/cmake/QtToolHelpers.cmake
+++ b/cmake/QtToolHelpers.cmake
@@ -712,14 +712,14 @@ function(qt_internal_find_tool out_var target_name tools_target)
         set(${tools_package_name}_BACKUP_CMAKE_FIND_ROOT_PATH "${CMAKE_FIND_ROOT_PATH}")
         if(QT_HOST_PATH_CMAKE_DIR)
             set(qt_host_path_cmake_dir_absolute "${QT_HOST_PATH_CMAKE_DIR}")
-        elseif(Qt${PROJECT_VERSION_MAJOR}HostInfo_DIR)
+        elseif(${INSTALL_CMAKE_NAMESPACE}HostInfo_DIR)
             get_filename_component(qt_host_path_cmake_dir_absolute
-                "${Qt${PROJECT_VERSION_MAJOR}HostInfo_DIR}/.." ABSOLUTE)
+                "${${INSTALL_CMAKE_NAMESPACE}HostInfo_DIR}/.." ABSOLUTE)
         else()
             # This should never happen, serves as an assert.
             message(FATAL_ERROR
                 "Neither QT_HOST_PATH_CMAKE_DIR nor "
-                "Qt${PROJECT_VERSION_MAJOR}HostInfo_DIR available.")
+                "${INSTALL_CMAKE_NAMESPACE}HostInfo_DIR available.")
         endif()
         set(CMAKE_PREFIX_PATH "${qt_host_path_cmake_dir_absolute}")