diff --git a/src/inputs.hpp b/src/inputs.hpp
index cffd5e4fa3437d9c0a8053e13f7bf47a8610288a..446aff7748dc1556a3e147fd1fa8fe228366c23e 100644
--- a/src/inputs.hpp
+++ b/src/inputs.hpp
@@ -26,7 +26,7 @@ struct GeometryAxis {
   bool periodic;
 };
 struct GeometrySettings {
-  std::tuple<GeometryAxis, GeometryAxis, GeometryAxis> axes;
+  std::array<GeometryAxis, 3> axes;
 };
 struct SolverSettings {
   GeometrySettings geometry;
diff --git a/src/inputs_file.cpp b/src/inputs_file.cpp
index dcc9cea3cbb60a5cb5b9daf50da702b1c143ac6a..8e59745055e108edc7bfc2b50dd671d5059e57e9 100644
--- a/src/inputs_file.cpp
+++ b/src/inputs_file.cpp
@@ -48,7 +48,7 @@ solver_settings::SolverSettings InputsFile::load() {
     return solver_settings::SolverSettings();
   }
   return maybe_solversettings.value();
-};
+}
 
 void InputsFile::save(solver_settings::SolverSettings settings) {
 
@@ -66,6 +66,6 @@ void InputsFile::save(solver_settings::SolverSettings settings) {
       << zz.high;
   ;
   out.close();
-};
+}
 
 } // namespace inputs_file
diff --git a/src/main.cpp b/src/main.cpp
index b4f7920eba7dba46737d9b354301ed5e36c0c366..10f93538c7648fbef7c7e3cbe9fb6185a8830cab 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -14,6 +14,10 @@ std::string read_file(std::string inputs_file) {
 }
 
 int main(int argc, char *argv[]) {
+  if (argc<2) {
+    std::cout << "Usage:  mfix-parser <inputs file>";
+    return -1;
+  }
   std::string fname(argv[1]);
   auto inputs_str = read_file(fname);
   auto maybe_success = parser::parse_inputs(inputs_str);