diff --git a/problems/identity-deformation.py b/problems/identity-deformation-dirichlet-values.py
similarity index 100%
rename from problems/identity-deformation.py
rename to problems/identity-deformation-dirichlet-values.py
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index bf5393d629333aab234d44cb4e7c29f7a6a6380d..ecb911fd36cb09aa1d5ae050755b8a022e7943f1 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,4 +1,4 @@
-if(ADOLC_FOUND AND IPOPT_FOUND AND PYTHONLIBS_FOUND AND dune-uggrid_FOUND)
+if(ADOLC_FOUND AND IPOPT_FOUND AND Python3_FOUND AND dune-uggrid_FOUND)
   set(programs linear-elasticity)
 
   # When combining dune-common 2.7 and dune-fufem 2.8, no cmake test for the
diff --git a/src/finite-strain-elasticity.cc b/src/finite-strain-elasticity.cc
index 411f9050013cf614d1b24c51f910be8eb24db30e..feff529f6a6aa342b1282da32de8ab77a2aeea1c 100644
--- a/src/finite-strain-elasticity.cc
+++ b/src/finite-strain-elasticity.cc
@@ -73,6 +73,8 @@ int main (int argc, char *argv[]) try
 
   // parse data file
   ParameterTree parameterSet;
+  if (argc < 2)
+    DUNE_THROW(Exception, "Usage: ./finite-strain-elasticity <parameter file>");
 
   ParameterTreeParser::readINITree(argv[1], parameterSet);