diff --git a/test/test_grammars.rb b/test/test_grammars.rb
index 00054a59..0a7260b8 100644
--- a/test/test_grammars.rb
+++ b/test/test_grammars.rb
@@ -15,6 +15,7 @@ class TestGrammars < Minitest::Test
     apache-2.0
     bsd-2-clause
     bsd-3-clause
+    isc
     mit
     mpl-2.0
     public
diff --git a/vendor/licenses/config.yml b/vendor/licenses/config.yml
index 0a8bd7a2..01fd4415 100644
--- a/vendor/licenses/config.yml
+++ b/vendor/licenses/config.yml
@@ -4,6 +4,7 @@ whitelist:
   - bsd-3-clause
   - permissive
   - mit
+  - isc
   - mpl-2.0
   - unlicense
   - wtfpl