diff --git a/dune/xt/functions/affine.hh b/dune/xt/functions/affine.hh
index 9aa3b9321481c0d76befd94f639bd8f98528c4e3..d6c98b1895f1df40006d2e991de6525d4044be0e 100644
--- a/dune/xt/functions/affine.hh
+++ b/dune/xt/functions/affine.hh
@@ -501,6 +501,11 @@ public:
     BaseType::template helper<>::jacobian_col(col, A_, ret);
   }
 
+  virtual bool is_affine() const override
+  {
+    return true;
+  }
+
 private:
   using BaseType::A_;
   using BaseType::b_;
diff --git a/dune/xt/functions/interfaces/localizable-flux-function.hh b/dune/xt/functions/interfaces/localizable-flux-function.hh
index 5cddfa06b8e12ad7a9e2e0151a1cde04b01e11c2..111dc278246b3a44e63c4305b23de771b53e4e84 100644
--- a/dune/xt/functions/interfaces/localizable-flux-function.hh
+++ b/dune/xt/functions/interfaces/localizable-flux-function.hh
@@ -68,6 +68,11 @@ public:
 
   virtual std::unique_ptr<LocalfunctionType> local_function(const EntityType& /*entity*/) const = 0;
 
+  virtual bool is_affine() const
+  {
+    return false;
+  }
+
   /**
    * \name ´´These methods should be implemented in order to identify the function.''
    * \{