diff --git a/navmap_rviz_plugin/CMakeLists.txt b/navmap_rviz_plugin/CMakeLists.txt
index c57108f..b8f8a24 100644
--- a/navmap_rviz_plugin/CMakeLists.txt
+++ b/navmap_rviz_plugin/CMakeLists.txt
@@ -3,6 +3,22 @@ project(navmap_rviz_plugin)
 
 find_package(ament_cmake REQUIRED)
 find_package(rclcpp REQUIRED)
+# Use the same Qt as rviz (Qt5 up to Kilted, Qt6 from Lyrical): mixing both breaks the plugin.
+# Read it from rviz_common's exported dependencies before find_package(rviz_common): a Qt5 rviz
+# looks for Qt6 first if installed and then fails to find Qt5, so Qt6 must be disabled.
+find_file(rviz_common_deps_file ament_cmake_export_dependencies-extras.cmake
+  PATHS ${CMAKE_PREFIX_PATH} ENV AMENT_PREFIX_PATH PATH_SUFFIXES share/rviz_common/cmake
+  NO_DEFAULT_PATH NO_CACHE)
+if(NOT rviz_common_deps_file)
+  message(FATAL_ERROR "rviz_common not found in CMAKE_PREFIX_PATH or AMENT_PREFIX_PATH")
+endif()
+file(READ "${rviz_common_deps_file}" rviz_common_deps)
+if(rviz_common_deps MATCHES "[\";]Qt6[\";]")
+  set(qt_major 6)
+else()
+  set(qt_major 5)
+  set(CMAKE_DISABLE_FIND_PACKAGE_Qt6 TRUE)
+endif()
 find_package(rviz_common REQUIRED)
 find_package(rviz_rendering REQUIRED)
 find_package(rviz_default_plugins REQUIRED)
@@ -12,14 +28,6 @@ find_package(navmap_ros_interfaces REQUIRED)
 find_package(navmap_ros REQUIRED)
 find_package(navmap_core REQUIRED)
 
-# Same Qt as rviz (Qt5 up to Kilted, Qt6 from Lyrical): mixing both breaks loading the plugin.
-# Ask rviz_common: other deps (e.g. VTK via PCL) may bring the other Qt along
-get_target_property(rviz_common_libs rviz_common::rviz_common INTERFACE_LINK_LIBRARIES)
-if("${rviz_common_libs}" MATCHES "Qt6::")
-  set(qt_major 6)
-else()
-  set(qt_major 5)
-endif()
 find_package(Qt${qt_major} REQUIRED COMPONENTS Widgets)
 
 qt_wrap_cpp(NAVMAP_MOC_SRCS