--- qt-assistant-4.7.4.ebuild
+++ qt-assistant-4.7.4.ebuild
@@ -58,6 +58,7 @@
 	if use compat; then
 		epatch "${FILESDIR}"/"${PN}"-4.7-fix-compat.patch
 	fi
+	sed -i -e "/^sub-qdoc3.depends/d" doc/doc.pri || die "sed failed"
 }
 
 src_configure() {