diff --git a/lib/sprockets/digest_utils.rb b/lib/sprockets/digest_utils.rb
index c6b2e39cd..7053d48a0 100644
--- a/lib/sprockets/digest_utils.rb
+++ b/lib/sprockets/digest_utils.rb
@@ -80,6 +80,9 @@ def detect_digest_class(bytes)
         digest << val.to_s
       }
     end
+
+    ADD_VALUE_TO_DIGEST.compare_by_identity.rehash
+
     ADD_VALUE_TO_DIGEST.default_proc = ->(_, val) {
       raise TypeError, "couldn't digest #{ val }"
     }