1 files changed, 1 insertions, 1 deletions
diff --git a/src/lib/kdf/kdf2/kdf2.h b/src/lib/kdf/kdf2/kdf2.h
index ad62ed301..7403df21c 100644
--- a/src/lib/kdf/kdf2/kdf2.h
+++ b/src/lib/kdf/kdf2/kdf2.h
@@ -27,7 +27,7 @@ class BOTAN_DLL KDF2 final : public KDF
                  const byte secret[], size_t secret_len,
                  const byte salt[], size_t salt_len) const override;
 
-      KDF2(HashFunction* h) : m_hash(h) {}
+      explicit KDF2(HashFunction* h) : m_hash(h) {}
    private:
       std::unique_ptr<HashFunction> m_hash;
    };