diff --git a/cmake/FindWrapDBus1.cmake b/cmake/FindWrapDBus1.cmake
index 3e0a31592c..42349a8b1a 100644
--- a/cmake/FindWrapDBus1.cmake
+++ b/cmake/FindWrapDBus1.cmake
@@ -1,10 +1,31 @@
 # DBus1 is buggy and breaks PKG_CONFIG environment.
 # Work around that:-/
+# See https://gitlab.freedesktop.org/dbus/dbus/issues/267 for more information
+
+if(DEFINED ENV{PKG_CONFIG_DIR})
+    set(__qt_dbus_pcd "$ENV{PKG_CONFIG_DIR}")
+endif()
+if(DEFINED ENV{PKG_CONFIG_PATH})
+    set(__qt_dbus_pcp "$ENV{PKG_CONFIG_PATH}")
+endif()
+if(DEFINED ENV{PKG_CONFIG_LIBDIR})
+    set(__qt_dbus_pcl "$ENV{PKG_CONFIG_LIBDIR}")
+endif()
 
-set(__qt_dbus_pcd $ENV{PKG_CONFIG_DIR})
-set(__qt_dbus_pcp $ENV{PKG_CONFIG_PATH})
-set(__qt_dbus_pcl $ENV{PKG_CONFIG_LIBDIR})
 find_package(DBus1)
-set(ENV{PKG_CONFIG_DIR} ${__qt_dbus_pcd})
-set(ENV{PKG_CONFIG_PATH} ${__qt_dbus_pcp})
-set(ENV{PKG_CONFIG_LIBDIR} ${__qt_dbus_pcl})
+
+if(DEFINED __qt_dbus_pcd)
+    set(ENV{PKG_CONFIG_DIR} "${__qt_dbus_pcd}")
+else()
+    unset(ENV{PKG_CONFIG_DIR})
+endif()
+if(DEFINED __qt_dbus_pcp)
+    set(ENV{PKG_CONFIG_PATH} "${__qt_dbus_pcp}")
+else()
+    unset(ENV{PKG_CONFIG_PATH})
+endif()
+if(DEFINED __qt_dbus_pcl)
+    set(ENV{PKG_CONFIG_LIBDIR} "${__qt_dbus_pcl}")
+else()
+    unset(ENV{PKG_CONFIG_LIBDIR})
+endif()