diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
index 371902bb75..a6a1dafa15 100755
--- a/ci/install-dependencies.sh
+++ b/ci/install-dependencies.sh
@@ -72,7 +72,7 @@ Documentation)
 		libcurl4-openssl-dev
 
 	test -n "$ALREADY_HAVE_ASCIIDOCTOR" ||
-	gem install --version 1.5.8 asciidoctor
+	sudo gem install --version 1.5.8 asciidoctor
 	;;
 GETTEXT_POISON)
 	sudo apt-get -q update