diff --git a/eclass/ecm.eclass b/eclass/ecm.eclass
index cafdf034329dc..31315f2b8d756 100644
--- a/eclass/ecm.eclass
+++ b/eclass/ecm.eclass
@@ -284,7 +284,7 @@ case ${ECM_QTHELP} in
 		COMMONDEPEND+=" doc? ( dev-qt/qt-docs:${_KFSLOT} )"
 		BDEPEND+=" doc? ( >=app-text/doxygen-1.8.13-r1 )"
 		if [[ ${_KFSLOT} == 6 ]]; then
-			BDEPEND+=" dev-qt/qttools:${_KFSLOT}[assistant]"
+			BDEPEND+=" doc? ( dev-qt/qttools:${_KFSLOT}[assistant] )"
 		else
 			BDEPEND+=" doc? ( dev-qt/qthelp:${_KFSLOT} )"
 		fi