diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 89dc2b25a6027b90eb55e9c7a96a58555b58d0b0..5c1aec5bcb938d9ba7b2038b1b3c4a46a1f8f79b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -20,6 +20,6 @@ test:cmake:
     - cmake -S. -Bbuild -GNinja -DCMAKE_BUILD_TYPE=Debug
     - cmake --build build --target unit_tests_csg
     - cd build
-    - ctest
+    - ctest --verbose
   tags:
     - mfix-exa
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4d0c5ce56bdadd995ad4ebcc3ab95d4766104e7d..f6798e3de7a41a16651e4716ab25a7ef10609be2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,8 +15,6 @@ if(CCACHE_FOUND)
   set( CMAKE_CXX_COMPILER_LAUNCHER ccache )
 endif()
 
-option(ENABLE_CSG "Build with CSG support" OFF)
-
 # Download automatically, you can also just copy the conan.cmake file
 if(NOT EXISTS "${CMAKE_BINARY_DIR}/conan.cmake")
   message(STATUS "Downloading conan.cmake from https://github.com/conan-io/cmake-conan")
@@ -37,7 +35,9 @@ include(Catch)
 
 add_subdirectory(src/csg)
 
-target_include_directories(csg PRIVATE
-  ${CONAN_INCLUDE_DIRS_PEGTL})
+target_include_directories(csg
+  PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src ${CONAN_INCLUDE_DIRS_PEGTL}
+  )
 
 target_compile_features(csg PRIVATE cxx_std_17)
diff --git a/src/csg/csg.hpp b/include/csg.hpp
similarity index 100%
rename from src/csg/csg.hpp
rename to include/csg.hpp
diff --git a/src/inputs/solver.hpp b/include/solver.hpp
similarity index 97%
rename from src/inputs/solver.hpp
rename to include/solver.hpp
index 0245e1ddc24bbdb1954704fab5f45903cef1a737..de49c869b6cc8bbcedb238cd142266045ed4a851 100644
--- a/src/inputs/solver.hpp
+++ b/include/solver.hpp
@@ -9,7 +9,7 @@
 #include <variant>
 #include <vector>
 
-#include <inputs.hpp>
+#include <solver_inputs.hpp>
 
 namespace solver {
 
diff --git a/meson.build b/meson.build
index 4cd3c5947e36d503e32b37c67aefaea7d241d6e7..a2fbacde50b732f683ef7ddb8bfde45682fd66f6 100644
--- a/meson.build
+++ b/meson.build
@@ -8,19 +8,7 @@ pegtl = dependency('pegtl', method: 'pkg-config')
 catch2 = dependency('catch2', method: 'pkg-config')
 cgal = dependency('cgal', method: 'pkg-config')
 
-parser_inc = include_directories(
-  'src/csg',
-  'src/csg/impl',
-  'src/inputs')
+parser_inc = include_directories('include', 'src')
 
 subdir('src/csg')
 subdir('src/inputs')
-
-executable(
-  'mfix-parser',
-  'src/main.cpp',
-  include_directories: parser_inc,
-  link_with: [
-    lib_csg_parser,
-    lib_inputs_parser,
-  ])
diff --git a/src/csg/CMakeLists.txt b/src/csg/CMakeLists.txt
index 58162524645cf4a39d77f107df0c66ec13c9e722..52452ccc97a9730d2e4ed95cdb871a2767714cec 100644
--- a/src/csg/CMakeLists.txt
+++ b/src/csg/CMakeLists.txt
@@ -1,17 +1,14 @@
 ################################################################################
 # CSG Parser
 ################################################################################
-add_library(csg)
-
-target_sources(csg PRIVATE
-  impl/parser.cpp
-  impl/levelset_3d.cpp
-  impl/levelset_2d.cpp
-  impl/csg.cpp
-  impl/matrix_functions.cpp
+add_library(csg
+  csg.cpp
+  levelset_2d.cpp
+  levelset_3d.cpp
+  matrix_functions.cpp
+  parser.cpp
   )
 
-target_include_directories(csg INTERFACE ${CMAKE_SOURCE_DIR})
 target_link_libraries(csg PRIVATE
                       stdc++fs
                       CONAN_PKG::cgal
diff --git a/src/csg/impl/csg.cpp b/src/csg/csg.cpp
similarity index 98%
rename from src/csg/impl/csg.cpp
rename to src/csg/csg.cpp
index 80fa8dd04b6933ce3aa051693eb86bee9fbdf559..8b7c17434a4d15c5683c09b2779a29462a98eb10 100644
--- a/src/csg/impl/csg.cpp
+++ b/src/csg/csg.cpp
@@ -2,7 +2,7 @@
 #include <iostream>
 #include <sstream>
 
-#include "../csg.hpp"
+#include "csg.hpp"
 
 #include "csg_types.hpp"
 
diff --git a/src/csg/impl/levelset_2d.cpp b/src/csg/levelset_2d.cpp
similarity index 100%
rename from src/csg/impl/levelset_2d.cpp
rename to src/csg/levelset_2d.cpp
diff --git a/src/csg/impl/levelset_3d.cpp b/src/csg/levelset_3d.cpp
similarity index 100%
rename from src/csg/impl/levelset_3d.cpp
rename to src/csg/levelset_3d.cpp
diff --git a/src/csg/impl/matrix_functions.cpp b/src/csg/matrix_functions.cpp
similarity index 97%
rename from src/csg/impl/matrix_functions.cpp
rename to src/csg/matrix_functions.cpp
index 4c0159d5d988a54290b85fe47e415b1f64ea4f9d..429471679832911831f3545844411cdce376b777 100644
--- a/src/csg/impl/matrix_functions.cpp
+++ b/src/csg/matrix_functions.cpp
@@ -1,4 +1,4 @@
-#include "matrix_functions.hpp"
+#include "csg_matrix_functions.hpp"
 
 namespace {
 double determinant(const matrix::Mat2d &m) {
diff --git a/src/csg/meson.build b/src/csg/meson.build
index a65bc68d4a8b92292b025ffcbf5304028c0532bc..c9f7140ed7259a289720df49a5fceb3109da3885 100644
--- a/src/csg/meson.build
+++ b/src/csg/meson.build
@@ -1,10 +1,11 @@
 lib_csg_parser = static_library(
   'csg-parser',
-  'impl/csg.cpp',
-  'impl/levelset_3d.cpp',
-  'impl/levelset_2d.cpp',
-  'impl/parser.cpp',
-  'impl/matrix_functions.cpp',
+  'csg.cpp',
+  'levelset_3d.cpp',
+  'levelset_2d.cpp',
+  'parser.cpp',
+  'matrix_functions.cpp',
+  include_directories: parser_inc,
   dependencies: [pegtl, cgal],
   install : true)
 
diff --git a/src/csg/impl/parser.cpp b/src/csg/parser.cpp
similarity index 100%
rename from src/csg/impl/parser.cpp
rename to src/csg/parser.cpp
diff --git a/src/csg/tests/CMakeLists.txt b/src/csg/tests/CMakeLists.txt
index 5476ad70989482defa76cef2ef91410f0a012b12..7ba26c7ca9984aaa60ec00ead9ca38b0d89e9aa1 100644
--- a/src/csg/tests/CMakeLists.txt
+++ b/src/csg/tests/CMakeLists.txt
@@ -4,21 +4,21 @@
 
 add_executable(unit_tests_csg EXCLUDE_FROM_ALL
   levelset/boolean.t.cpp
+  levelset/extrude.t.cpp
   levelset/primitives.t.cpp
   levelset/transform.t.cpp
-  levelset/extrude.t.cpp
   parser/boolean.t.cpp
-  parser/main.cpp
+  parser/extrude.t.cpp
   parser/nest.cpp
   parser/other.t.cpp
   parser/primitives.t.cpp
   parser/transform.t.cpp
-  parser/extrude.t.cpp
+  unit_tests_csg.main.cpp
   )
 
-target_include_directories(unit_tests_csg PRIVATE
-  ..
-  ../impl
+target_include_directories(unit_tests_csg
+  PUBLIC ${CMAKE_SOURCE_DIR}/include
+  PRIVATE ${CMAKE_SOURCE_DIR}/src
   ${CONAN_INCLUDE_DIRS_CATCH2}
   )
 
diff --git a/src/csg/tests/levelset/extrude.t.cpp b/src/csg/tests/levelset/extrude.t.cpp
index 6629bed95950ddcae36bd77531955bf00224360e..74404cf9d65c01acff45d1952ff3333cc492531a 100644
--- a/src/csg/tests/levelset/extrude.t.cpp
+++ b/src/csg/tests/levelset/extrude.t.cpp
@@ -2,7 +2,7 @@
 
 #include <csg.hpp>
 #include <csg_types.hpp>
-#include <matrix_functions.hpp>
+#include <csg_matrix_functions.hpp>
 
 namespace {
 
diff --git a/src/csg/tests/levelset/transform.t.cpp b/src/csg/tests/levelset/transform.t.cpp
index 14617503343e194f1d2082adf863f2dbd1b83a40..99bf3ef1cf19b2be9b253a969086738b9bf5c2cb 100644
--- a/src/csg/tests/levelset/transform.t.cpp
+++ b/src/csg/tests/levelset/transform.t.cpp
@@ -4,7 +4,7 @@
 
 #include <csg.hpp>
 #include <csg_types.hpp>
-#include <matrix_functions.hpp>
+#include <csg_matrix_functions.hpp>
 
 namespace {
 
diff --git a/src/csg/tests/meson.build b/src/csg/tests/meson.build
index b4f9e61677118253c23b3a3e465d6353f5aa8163..3051eab38b68a20003380649a7865d333298d53c 100644
--- a/src/csg/tests/meson.build
+++ b/src/csg/tests/meson.build
@@ -1,16 +1,16 @@
 test_csg = executable(
   'unit_tests_csg',
   'levelset/boolean.t.cpp',
+  'levelset/extrude.t.cpp',
   'levelset/primitives.t.cpp',
   'levelset/transform.t.cpp',
-  'levelset/extrude.t.cpp',
   'parser/boolean.t.cpp',
-  'parser/main.cpp',
+  'parser/extrude.t.cpp',
   'parser/nest.cpp',
   'parser/other.t.cpp',
   'parser/primitives.t.cpp',
   'parser/transform.t.cpp',
-  'parser/extrude.t.cpp',
+  'unit_tests_csg.main.cpp',
   include_directories: [parser_inc],
   dependencies: [catch2, cgal],
   link_with: lib_csg_parser,
diff --git a/src/csg/tests/parser/main.cpp b/src/csg/tests/unit_tests_csg.main.cpp
similarity index 100%
rename from src/csg/tests/parser/main.cpp
rename to src/csg/tests/unit_tests_csg.main.cpp
diff --git a/src/csg/impl/matrix_functions.hpp b/src/csg_matrix_functions.hpp
similarity index 100%
rename from src/csg/impl/matrix_functions.hpp
rename to src/csg_matrix_functions.hpp
diff --git a/src/csg/impl/csg_types.hpp b/src/csg_types.hpp
similarity index 99%
rename from src/csg/impl/csg_types.hpp
rename to src/csg_types.hpp
index 0cf25494e37ca86160da2dca5fcc540e8b701a65..5077100942fe8e0a4c5185230a3e51804334700a 100644
--- a/src/csg/impl/csg_types.hpp
+++ b/src/csg_types.hpp
@@ -1,7 +1,7 @@
 #ifndef CSG_TYPES_H_
 #define CSG_TYPES_H_
 
-#include "matrix_functions.hpp"
+#include "csg_matrix_functions.hpp"
 
 #include <array>
 #include <memory>
diff --git a/src/inputs/meson.build b/src/inputs/meson.build
index 3e993c7f3c1acda088d6d430784399061e0e795c..ecc738394d6cad8c26466dabb75f11b485963478 100644
--- a/src/inputs/meson.build
+++ b/src/inputs/meson.build
@@ -5,7 +5,17 @@ lib_inputs_parser = static_library(
   'parser.cpp',
   'solver.cpp',
   'time.cpp',
+  include_directories: parser_inc,
   dependencies: [pegtl],
   install : true)
 
+executable(
+  'mfix-parser',
+  'mfix-parser.main.cpp',
+  include_directories: parser_inc,
+  link_with: [
+    lib_csg_parser,
+    lib_inputs_parser,
+  ])
+
 subdir('tests')
diff --git a/src/main.cpp b/src/inputs/mfix-parser.main.cpp
similarity index 100%
rename from src/main.cpp
rename to src/inputs/mfix-parser.main.cpp
diff --git a/src/inputs/tests/meson.build b/src/inputs/tests/meson.build
index 0d0fa2409ffad2376f85d50c18bc449e7929ed42..68dfcaf0e2114b326b92b73141a58e93fb6ca936 100644
--- a/src/inputs/tests/meson.build
+++ b/src/inputs/tests/meson.build
@@ -2,7 +2,7 @@ test_inputs = executable(
   'unit_tests_inputs',
   'parser.t.cpp',
   'solver.t.cpp',
-  'main.cpp',
+  'unit_tests_inputs.main.cpp',
   include_directories: [parser_inc],
   dependencies: [catch2],
   link_with: lib_inputs_parser
diff --git a/src/inputs/tests/solver.t.cpp b/src/inputs/tests/solver.t.cpp
index c7343f4fb9073b39da0237c36fc31775460c804c..580175235de25288e89016897517a2c8f5be2b9a 100644
--- a/src/inputs/tests/solver.t.cpp
+++ b/src/inputs/tests/solver.t.cpp
@@ -1,6 +1,6 @@
 #include "catch2/catch.hpp"
 
-#include <inputs.hpp>
+#include <solver_inputs.hpp>
 #include <solver_impl.hpp>
 
 TEST_CASE("GeometrySettings", "[]") {
diff --git a/src/inputs/tests/main.cpp b/src/inputs/tests/unit_tests_inputs.main.cpp
similarity index 100%
rename from src/inputs/tests/main.cpp
rename to src/inputs/tests/unit_tests_inputs.main.cpp
diff --git a/src/inputs/solver_impl.hpp b/src/solver_impl.hpp
similarity index 100%
rename from src/inputs/solver_impl.hpp
rename to src/solver_impl.hpp
diff --git a/src/inputs/inputs.hpp b/src/solver_inputs.hpp
similarity index 100%
rename from src/inputs/inputs.hpp
rename to src/solver_inputs.hpp