diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index a1e2dd8d..d74cef36 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -21,6 +21,7 @@ jobs:
         features:
           - '--no-default-features'
           - ''
+          - '--features value-no-dup-keys'
           - '--features known-key'
           - '--features 128bit'
           - '--features beef'