diff --git a/CHANGELOG.md b/CHANGELOG.md
index ab567cc6b..035388d0d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -47,7 +47,7 @@ SPDX-License-Identifier: LGPL-3.0-or-later
         - The assembler bindings now also accept affordances and `DBCOption`, and they are also renamed to simply `matrix`, `vector`
           and `scalar`.
         - The assemblers also export the binding functions to bind the assemblers.
-- Rework Python Interface for `DirichletValues` plus adding support to easily fix boundary DOFs of subspacebasis in C++ and Python ([#305](https://github.com/ikarus-project/ikarus/pull/305))
+- Rework the Python Interface for `DirichletValues` plus add support to easily fix boundary DOFs of `Subspacebasis` in C++ and Python ([#305](https://github.com/ikarus-project/ikarus/pull/305))
 
 ## Release v0.4 (Ganymede)
 
diff --git a/docs/website/01_framework/dirichletBCs.md b/docs/website/01_framework/dirichletBCs.md
index 45083e31b..22cd30457 100644
--- a/docs/website/01_framework/dirichletBCs.md
+++ b/docs/website/01_framework/dirichletBCs.md
@@ -24,25 +24,25 @@ The interface of `#!cpp Ikarus::DirichletValues` is represented by the following
 Ikarus::DirichletValues dirichletValues2(basis); // (1)!
 void fixBoundaryDOFs(f); // (2)!
 void fixDOFs(f); // (3)!
-void setSingleDOF(i, bool flag); // (4)!
+void setSingleDOF(i, flag); // (4)!
 const auto& basis() const; // (5)!
-bool isConstrained(std::size_t i) const; // (6)!
+bool isConstrained(i) const; // (6)!
 auto fixedDOFsize() const; // (7)!
 auto size() const ; // (8)!
 auto reset(); // (9)!
 ```
 
 1. Create class by inserting a global basis, [@sander2020dune] Chapter 10.
-2. Accepts a functor to fix boundary degrees of freedom. `f` is  a functor that will be called with the boolean vector of fixed boundary.
+2. Accepts a functor to fix boundary degrees of freedom. `f` is  a functor that will be called with the Boolean vector of fixed boundary.
  degrees of freedom and the usual arguments of `Dune::Functions::forEachBoundaryDOF`, as defined on page 388 of the Dune
    [@sander2020dune] book.
-3. A more general version of `fixBoundaryDOFs`. Here, a functor is to be provided that accepts a basis and the corresponding boolean
+3. A more general version of `fixBoundaryDOFs`. Here, a functor is to be provided that accepts a basis and the corresponding Boolean
 4. A function that helps to fix or unfix the $i$-th degree of freedom
    vector considering the Dirichlet degrees of freedom.
 5. Returns the underlying basis.
-6. Indicates whether the degree of freedom `i` is fixed.
+6. Indicates whether the degree of freedom $i$ is fixed.
 7. Returns the number of fixed degrees of freedom.
-8. Returns the number of all dirichlet degrees of freedom.
+8. Returns the number of all Dirichlet degrees of freedom.
 9. Resets the whole container
 
 \bibliography
diff --git a/ikarus/python/test/CMakeLists.txt b/ikarus/python/test/CMakeLists.txt
index e49554b13..ddcf6e290 100644
--- a/ikarus/python/test/CMakeLists.txt
+++ b/ikarus/python/test/CMakeLists.txt
@@ -38,7 +38,7 @@ dune_python_add_test(
   NAME
   pydirichletvalues
   SCRIPT
-  testdirichletvalues.py
+  dirichletvaluetest.py
   WORKING_DIRECTORY
   ${CMAKE_CURRENT_SOURCE_DIR}
   LABELS
diff --git a/ikarus/python/test/testdirichletvalues.py b/ikarus/python/test/dirichletvaluetest.py
similarity index 100%
rename from ikarus/python/test/testdirichletvalues.py
rename to ikarus/python/test/dirichletvaluetest.py
diff --git a/ikarus/utils/dirichletvalues.hh b/ikarus/utils/dirichletvalues.hh
index 4dc713ce8..75f6687ef 100644
--- a/ikarus/utils/dirichletvalues.hh
+++ b/ikarus/utils/dirichletvalues.hh
@@ -87,6 +87,8 @@ public:
         f(dirichletFlagsBackend_, localIndex, localView, intersection);
       };
       Dune::Functions::forEachBoundaryDOF(subspaceBasis(basis_, std::forward<TreePath>(treePath)), lambda);
+    } else {
+      static_assert(Dune::AlwaysFalse<F>(), "fixBoundaryDOFs: A function with this signature is not supported");
     }
   }
 
@@ -104,7 +106,7 @@ public:
   }
 
   /**
-   * \brief Fixes (set boolean value to true) a specific degree of freedom
+   * \brief Fixes and unfixes (set boolean value to true or false) a specific degree of freedom
    *
    * \param i An index indicating the DOF number to be fixed
    * \param flag Boolean indicating whether the DOF should fixed or not
@@ -116,7 +118,7 @@ public:
   }
 
   /**
-   * \brief Fixes (set boolean value to true) a specific degree of freedom
+   * \brief Fixes or unfixes (set boolean value to true or flase) a specific degree of freedom
    *
    * \param i An index indicating the DOF number to be fixed
    * \param flag Boolean indicating whether the DOF should fixed or not