diff --git a/doc/conf.py b/doc/conf.py
index 8a68d856fc9..f851b791b5c 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -185,6 +185,7 @@ doxyrunner_doxyfile = ZEPHYR_BASE / "doc" / "zephyr.doxyfile.in"
 doxyrunner_outdir = ZEPHYR_BUILD / "doxygen"
 doxyrunner_fmt = True
 doxyrunner_fmt_vars = {"ZEPHYR_BASE": str(ZEPHYR_BASE), "ZEPHYR_VERSION": version}
+doxyrunner_outdir_var = "DOXY_OUT"
 
 # -- Options for Breathe plugin -------------------------------------------