diff --git a/include/hibf/interleaved_bloom_filter.hpp b/include/hibf/interleaved_bloom_filter.hpp
index acc9e45e..b29d6ab8 100644
--- a/include/hibf/interleaved_bloom_filter.hpp
+++ b/include/hibf/interleaved_bloom_filter.hpp
@@ -147,7 +147,7 @@ class interleaved_bloom_filter : private seqan::hibf::bit_vector
 
     //!\brief Allow cereal to cast the IBF into its base class.
     template <typename t>
-    friend class cereal::base_class;
+    friend struct cereal::base_class;
 
     //!\brief The number of bins specified by the user.
     size_t bins{};