diff --git a/dev-ruby/rbnacl/rbnacl-4.0.2.ebuild b/dev-ruby/rbnacl/rbnacl-4.0.2.ebuild
index ab73721d1e12c..9a21d0ad14e36 100644
--- a/dev-ruby/rbnacl/rbnacl-4.0.2.ebuild
+++ b/dev-ruby/rbnacl/rbnacl-4.0.2.ebuild
@@ -23,6 +23,8 @@ IUSE=""
 RDEPEND+=" dev-libs/libsodium"
 DEPEND+=" test? ( dev-libs/libsodium )"
 
+ruby_add_rdepend "dev-ruby/ffi"
+
 all_ruby_prepare() {
 	sed -i -e '/coveralls/I s:^:#:' \
 		-e '/bundler/ s:^:#:' \
diff --git a/dev-ruby/rbnacl/rbnacl-5.0.0.ebuild b/dev-ruby/rbnacl/rbnacl-5.0.0.ebuild
index 5ec64d2b6f3a8..eb435dee8db91 100644
--- a/dev-ruby/rbnacl/rbnacl-5.0.0.ebuild
+++ b/dev-ruby/rbnacl/rbnacl-5.0.0.ebuild
@@ -23,6 +23,8 @@ IUSE=""
 RDEPEND+=" dev-libs/libsodium"
 DEPEND+=" test? ( dev-libs/libsodium )"
 
+ruby_add_rdepend "dev-ruby/ffi"
+
 all_ruby_prepare() {
 	sed -i -e '/coveralls/I s:^:#:' \
 		-e '/bundler/ s:^:#:' \