diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2408b54..f9da54a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -204,27 +204,13 @@ else()
 endif()
 
 if(LUSOL)
-   include(CheckLanguage)
-   check_language(Fortran)
    find_package(BLAS)
-endif()
-if(CMAKE_Fortran_COMPILER AND BLAS_FOUND)
-   enable_language(Fortran)
-
-   add_library(clusol STATIC
-      src/papilo/external/lusol/src/lusol6b.f
-      src/papilo/external/lusol/src/lusol7b.f
-      src/papilo/external/lusol/src/lusol8b.f
-      src/papilo/external/lusol/src/lusol_util.f
-      src/papilo/external/lusol/src/lusol.f90
-      src/papilo/external/lusol/src/clusol.c
-      src/papilo/external/lusol/src/lusol_precision.f90)
-   set_property(TARGET clusol PROPERTY POSITION_INDEPENDENT_CODE ON)
-   target_include_directories(clusol PRIVATE src/papilo/external/lusol)
-   target_link_libraries(clusol ${BLAS_LIBRARIES})
+   if(BLAS_FOUND)
+      target_link_libraries(papilo INTERFACE ${BLAS_LIBRARIES})
+   endif()
    target_link_libraries(papilo INTERFACE clusol)
    set(PAPILO_HAVE_LUSOL 1)
-   set(CLUSOL_TARGET clusol)
+   set(CLUSOL_TARGET "")
 else()
    set(PAPILO_HAVE_LUSOL 0)
    set(CLUSOL_TARGET "")
@@ -245,17 +231,7 @@ if(NOT MSVC)
       endif()
    endif()
 endif()
-set(CMAKE_REQUIRED_INCLUDES ${PROJECT_SOURCE_DIR}/src/papilo/external)
-check_cxx_source_compiles(
-   "#include \"ska/bytell_hash_map.hpp\"
-   int main() { ska::bytell_hash_map<int,int> hashmap; (void)hashmap; return 0; }"
-   PAPILO_BYTELL_HASHMAP_WORKS )
-
-if( PAPILO_BYTELL_HASHMAP_WORKS )
-   set(PAPILO_USE_STANDARD_HASHMAP 0)
-else()
-   set(PAPILO_USE_STANDARD_HASHMAP 1)
-endif()
+set(PAPILO_USE_STANDARD_HASHMAP 1)
 
 add_library(papilo-core STATIC
    src/papilo/core/VariableDomains.cpp
@@ -458,20 +434,6 @@ install(FILES
      ${PROJECT_SOURCE_DIR}/src/papilo/external/fmt/ranges.h
  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/papilo/external/fmt)
 
-install(FILES
-     ${PROJECT_SOURCE_DIR}/src/papilo/external/pdqsort/pdqsort.h
-  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/papilo/external/pdqsort)
-
-install(FILES
-     ${PROJECT_SOURCE_DIR}/src/papilo/external/ska/bytell_hash_map.hpp
-     ${PROJECT_SOURCE_DIR}/src/papilo/external/ska/flat_hash_map.hpp
-     ${PROJECT_SOURCE_DIR}/src/papilo/external/ska/unordered_map.hpp
-  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/papilo/external/ska)
-
-install(FILES
-     ${PROJECT_SOURCE_DIR}/src/papilo/external/lusol/clusol.h
-  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/papilo/external/lusol)
-
 # configure the config file for the build tree
 set(QUADMATH_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/Modules)
 set(TBB_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/Modules)
diff --git a/src/convMPS.cpp b/src/convMPS.cpp
index 2398c4f..5897b9a 100644
--- a/src/convMPS.cpp
+++ b/src/convMPS.cpp
@@ -36,7 +36,7 @@
 #ifdef PAPILO_TBB
 #include "papilo/misc/tbb.hpp"
 #endif
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 #include "tbb/concurrent_unordered_set.h"
 #include <algorithm>
 
diff --git a/src/duplicates.cpp b/src/duplicates.cpp
index 5767e29..bfbee3d 100644
--- a/src/duplicates.cpp
+++ b/src/duplicates.cpp
@@ -30,7 +30,7 @@
 #ifdef PAPILO_TBB
 #include "papilo/misc/tbb.hpp"
 #endif
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 #include <algorithm>
 #include <sys/stat.h>
 
diff --git a/src/papilo/core/Components.hpp b/src/papilo/core/Components.hpp
index f27cd1c..9502e0f 100644
--- a/src/papilo/core/Components.hpp
+++ b/src/papilo/core/Components.hpp
@@ -26,7 +26,7 @@
 #include "papilo/core/Problem.hpp"
 #include "papilo/misc/Hash.hpp"
 #include "papilo/misc/Vec.hpp"
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 #include <boost/pending/disjoint_sets.hpp>
 
 namespace papilo
diff --git a/src/papilo/core/SparseStorage.hpp b/src/papilo/core/SparseStorage.hpp
index ce55c4d..bd0908e 100644
--- a/src/papilo/core/SparseStorage.hpp
+++ b/src/papilo/core/SparseStorage.hpp
@@ -25,7 +25,7 @@
 
 #include "papilo/misc/MultiPrecision.hpp"
 #include "papilo/misc/Vec.hpp"
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 #include <algorithm>
 #include <cassert>
 #include <cstdint>
diff --git a/src/papilo/io/MpsParser.hpp b/src/papilo/io/MpsParser.hpp
index f8ec4ba..ca840d3 100644
--- a/src/papilo/io/MpsParser.hpp
+++ b/src/papilo/io/MpsParser.hpp
@@ -29,7 +29,7 @@
 #include "papilo/core/Objective.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/VariableDomains.hpp"
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 #include "papilo/io/BoundType.hpp"
 #include "papilo/io/ParseKey.hpp"
 #include "papilo/misc/Flags.hpp"
diff --git a/src/papilo/io/OpbParser.hpp b/src/papilo/io/OpbParser.hpp
index 9920b19..c4e423c 100644
--- a/src/papilo/io/OpbParser.hpp
+++ b/src/papilo/io/OpbParser.hpp
@@ -28,7 +28,7 @@
 #include "papilo/core/Objective.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/VariableDomains.hpp"
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 #include "papilo/io/BoundType.hpp"
 #include "papilo/io/ParseKey.hpp"
 #include "papilo/misc/Flags.hpp"
diff --git a/src/papilo/misc/DependentRows.hpp b/src/papilo/misc/DependentRows.hpp
index 557c7b7..90b7563 100644
--- a/src/papilo/misc/DependentRows.hpp
+++ b/src/papilo/misc/DependentRows.hpp
@@ -28,7 +28,7 @@
 #ifdef PAPILO_HAVE_LUSOL
 extern "C"
 {
-#include "papilo/external/lusol/clusol.h"
+#include <clusol.h>
 }
 #endif
 
diff --git a/src/papilo/presolvers/FreeVarSubstitution.hpp b/src/papilo/presolvers/FreeVarSubstitution.hpp
index 9687f13..6bcc6b3 100644
--- a/src/papilo/presolvers/FreeVarSubstitution.hpp
+++ b/src/papilo/presolvers/FreeVarSubstitution.hpp
@@ -28,7 +28,7 @@
 #include "papilo/core/ProblemUpdate.hpp"
 #include "papilo/misc/Num.hpp"
 #include "papilo/misc/fmt.hpp"
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 #include <boost/dynamic_bitset.hpp>
 
 namespace papilo
diff --git a/src/papilo/presolvers/ParallelColDetection.hpp b/src/papilo/presolvers/ParallelColDetection.hpp
index f353a5d..ecbd8e3 100644
--- a/src/papilo/presolvers/ParallelColDetection.hpp
+++ b/src/papilo/presolvers/ParallelColDetection.hpp
@@ -30,7 +30,7 @@
 #ifdef PAPILO_TBB
 #include "papilo/misc/tbb.hpp"
 #endif
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 
 namespace papilo
 {
diff --git a/src/papilo/presolvers/ParallelRowDetection.hpp b/src/papilo/presolvers/ParallelRowDetection.hpp
index 11e5cee..e85b853 100644
--- a/src/papilo/presolvers/ParallelRowDetection.hpp
+++ b/src/papilo/presolvers/ParallelRowDetection.hpp
@@ -30,7 +30,7 @@
 #ifdef PAPILO_TBB
 #include "papilo/misc/tbb.hpp"
 #endif
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 
 namespace papilo
 {
diff --git a/src/papilo/presolvers/SimplifyInequalities.hpp b/src/papilo/presolvers/SimplifyInequalities.hpp
index 3d80ba0..5381940 100644
--- a/src/papilo/presolvers/SimplifyInequalities.hpp
+++ b/src/papilo/presolvers/SimplifyInequalities.hpp
@@ -26,7 +26,7 @@
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemUpdate.hpp"
-#include "papilo/external/pdqsort/pdqsort.h"
+#include <pdqsort.h>
 #include <boost/integer/common_factor.hpp>
 
 namespace papilo
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 57f783c..d32eb4f 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -59,7 +59,7 @@ add_executable(unit_test TestMain.cpp
         ${BOOST_REQUIRED_TEST_FILES}
         ${PAPILOLIB_TEST_FILE})
 
-target_link_libraries(unit_test papilo ${PAPILOLIB_TARGET} ${Boost_LIBRARIES})
+target_link_libraries(unit_test papilo ${PAPILOLIB_TARGET} ${Boost_LIBRARIES} Catch2 Catch2Main)
 if(${CMAKE_SYSTEM_NAME} STREQUAL "Android")
     target_link_libraries(unit_test log)
 endif()
diff --git a/test/PapiloLib.cpp b/test/PapiloLib.cpp
index 10d55b2..f8dd379 100644
--- a/test/PapiloLib.cpp
+++ b/test/PapiloLib.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilolib.h"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/misc/fmt.hpp"
 
 TEST_CASE( "papilolib", "[C-API]" )
@@ -441,8 +441,8 @@ TEST_CASE( "papilolib", "[C-API]" )
    PAPILO_SOLVING_INFO* result = papilo_solver_start( solver );
 
    REQUIRE( result->solve_result == PAPILO_SOLVE_RESULT_OPTIMAL );
-   REQUIRE( result->bestsol_obj == Approx( 796648.4375 ) );
-   REQUIRE( result->dualbound == Approx( 796648.4375 ) );
+   REQUIRE( result->bestsol_obj == Catch::Approx( 796648.4375 ) );
+   REQUIRE( result->dualbound == Catch::Approx( 796648.4375 ) );
    REQUIRE( result->bestsol_intviol >= 0.0 );
    REQUIRE( result->bestsol_boundviol >= 0.0 );
    REQUIRE( result->bestsol_consviol >= 0.0 );
@@ -456,7 +456,7 @@ TEST_CASE( "papilolib", "[C-API]" )
    double objval = 0;
    for( int i = 0; i < nvars; ++i )
       objval += obj[i] * sol[i];
-   REQUIRE( objval == Approx( 796648.4375 ) );
+   REQUIRE( objval == Catch::Approx( 796648.4375 ) );
 
    papilo_solver_free( solver );
 }
diff --git a/test/TestMain.cpp b/test/TestMain.cpp
index 689f088..5a5b5a9 100644
--- a/test/TestMain.cpp
+++ b/test/TestMain.cpp
@@ -22,4 +22,4 @@
 
 #define CATCH_CONFIG_MAIN
 
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
diff --git a/test/papilo/core/MatrixBufferTest.cpp b/test/papilo/core/MatrixBufferTest.cpp
index ef63d4c..bb4305a 100644
--- a/test/papilo/core/MatrixBufferTest.cpp
+++ b/test/papilo/core/MatrixBufferTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/core/MatrixBuffer.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/misc/fmt.hpp"
 
 using namespace papilo;
diff --git a/test/papilo/core/PostsolveTest.cpp b/test/papilo/core/PostsolveTest.cpp
index 701382e..2374fc8 100644
--- a/test/papilo/core/PostsolveTest.cpp
+++ b/test/papilo/core/PostsolveTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/core/postsolve/Postsolve.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/postsolve/PostsolveStatus.hpp"
 #include <boost/archive/binary_iarchive.hpp>
 
diff --git a/test/papilo/core/PresolveTest.cpp b/test/papilo/core/PresolveTest.cpp
index 7ac214a..16cdac2 100644
--- a/test/papilo/core/PresolveTest.cpp
+++ b/test/papilo/core/PresolveTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/core/Presolve.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
 #include "papilo/core/Reductions.hpp"
diff --git a/test/papilo/core/ProblemUpdateTest.cpp b/test/papilo/core/ProblemUpdateTest.cpp
index 94c9b36..a3f8ed9 100644
--- a/test/papilo/core/ProblemUpdateTest.cpp
+++ b/test/papilo/core/ProblemUpdateTest.cpp
@@ -20,7 +20,7 @@
 /*                                                                           */
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
 #include "papilo/core/Reductions.hpp"
diff --git a/test/papilo/core/SparseStorageTest.cpp b/test/papilo/core/SparseStorageTest.cpp
index dbe1d2c..a739d03 100644
--- a/test/papilo/core/SparseStorageTest.cpp
+++ b/test/papilo/core/SparseStorageTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/core/SparseStorage.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/misc/compress_vector.hpp"
 
 papilo::SparseStorage<double>
diff --git a/test/papilo/io/MpsParserTest.cpp b/test/papilo/io/MpsParserTest.cpp
index 6c01343..fe43ea5 100644
--- a/test/papilo/io/MpsParserTest.cpp
+++ b/test/papilo/io/MpsParserTest.cpp
@@ -22,7 +22,7 @@
 
 #include <memory>
 #include "papilo/io/MpsParser.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 
diff --git a/test/papilo/misc/VectorUtilsTest.cpp b/test/papilo/misc/VectorUtilsTest.cpp
index 691f0d0..5116877 100644
--- a/test/papilo/misc/VectorUtilsTest.cpp
+++ b/test/papilo/misc/VectorUtilsTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/misc/VectorUtils.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 
 using namespace papilo;
 
diff --git a/test/papilo/presolve/CoefficientStrengtheningTest.cpp b/test/papilo/presolve/CoefficientStrengtheningTest.cpp
index 9b55947..f6e58d5 100644
--- a/test/papilo/presolve/CoefficientStrengtheningTest.cpp
+++ b/test/papilo/presolve/CoefficientStrengtheningTest.cpp
@@ -20,7 +20,7 @@
 /*                                                                           */
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/ConstraintPropagationTest.cpp b/test/papilo/presolve/ConstraintPropagationTest.cpp
index a1c16bd..538d617 100644
--- a/test/papilo/presolve/ConstraintPropagationTest.cpp
+++ b/test/papilo/presolve/ConstraintPropagationTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/ConstraintPropagation.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/DominatedColsTest.cpp b/test/papilo/presolve/DominatedColsTest.cpp
index 5915b5b..4775269 100644
--- a/test/papilo/presolve/DominatedColsTest.cpp
+++ b/test/papilo/presolve/DominatedColsTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/DominatedCols.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/DualFixTest.cpp b/test/papilo/presolve/DualFixTest.cpp
index 95edefd..583730a 100644
--- a/test/papilo/presolve/DualFixTest.cpp
+++ b/test/papilo/presolve/DualFixTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/DualFix.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/FixContinuousTest.cpp b/test/papilo/presolve/FixContinuousTest.cpp
index c6278ec..b9857d6 100644
--- a/test/papilo/presolve/FixContinuousTest.cpp
+++ b/test/papilo/presolve/FixContinuousTest.cpp
@@ -20,7 +20,7 @@
 /*                                                                           */
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/FreeVarSubstitutionTest.cpp b/test/papilo/presolve/FreeVarSubstitutionTest.cpp
index 36df2ca..36a7f43 100644
--- a/test/papilo/presolve/FreeVarSubstitutionTest.cpp
+++ b/test/papilo/presolve/FreeVarSubstitutionTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/FreeVarSubstitution.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/ImplIntDetectionTest.cpp b/test/papilo/presolve/ImplIntDetectionTest.cpp
index ee8a85b..9937677 100644
--- a/test/papilo/presolve/ImplIntDetectionTest.cpp
+++ b/test/papilo/presolve/ImplIntDetectionTest.cpp
@@ -20,7 +20,7 @@
 /*                                                                           */
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/ParallelColDetectionTest.cpp b/test/papilo/presolve/ParallelColDetectionTest.cpp
index 125f3b0..642ce0e 100644
--- a/test/papilo/presolve/ParallelColDetectionTest.cpp
+++ b/test/papilo/presolve/ParallelColDetectionTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/ParallelColDetection.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/ParallelRowDetectionTest.cpp b/test/papilo/presolve/ParallelRowDetectionTest.cpp
index dd9a582..13033d6 100644
--- a/test/papilo/presolve/ParallelRowDetectionTest.cpp
+++ b/test/papilo/presolve/ParallelRowDetectionTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/ParallelRowDetection.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/ProbingTest.cpp b/test/papilo/presolve/ProbingTest.cpp
index 3da0e57..4a78128 100644
--- a/test/papilo/presolve/ProbingTest.cpp
+++ b/test/papilo/presolve/ProbingTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/Probing.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/SimpleProbingTest.cpp b/test/papilo/presolve/SimpleProbingTest.cpp
index 4d2bd86..0d6e542 100644
--- a/test/papilo/presolve/SimpleProbingTest.cpp
+++ b/test/papilo/presolve/SimpleProbingTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/SimpleProbing.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/SimpleSubstitutionTest.cpp b/test/papilo/presolve/SimpleSubstitutionTest.cpp
index 5514d61..723f48b 100644
--- a/test/papilo/presolve/SimpleSubstitutionTest.cpp
+++ b/test/papilo/presolve/SimpleSubstitutionTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/SimpleSubstitution.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/SimplifyInequalitiesTest.cpp b/test/papilo/presolve/SimplifyInequalitiesTest.cpp
index 200f4b9..a108b05 100644
--- a/test/papilo/presolve/SimplifyInequalitiesTest.cpp
+++ b/test/papilo/presolve/SimplifyInequalitiesTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/SimplifyInequalities.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/SingletonColsTest.cpp b/test/papilo/presolve/SingletonColsTest.cpp
index f00244f..da0a518 100644
--- a/test/papilo/presolve/SingletonColsTest.cpp
+++ b/test/papilo/presolve/SingletonColsTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/SingletonCols.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/SingletonStuffingTest.cpp b/test/papilo/presolve/SingletonStuffingTest.cpp
index 8a5b3cf..84be4ee 100644
--- a/test/papilo/presolve/SingletonStuffingTest.cpp
+++ b/test/papilo/presolve/SingletonStuffingTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/SingletonStuffing.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"
diff --git a/test/papilo/presolve/SparsifyTest.cpp b/test/papilo/presolve/SparsifyTest.cpp
index fb0440e..afde146 100644
--- a/test/papilo/presolve/SparsifyTest.cpp
+++ b/test/papilo/presolve/SparsifyTest.cpp
@@ -21,7 +21,7 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "papilo/presolvers/Sparsify.hpp"
-#include "papilo/external/catch/catch.hpp"
+#include <catch2/catch_all.hpp>
 #include "papilo/core/PresolveMethod.hpp"
 #include "papilo/core/Problem.hpp"
 #include "papilo/core/ProblemBuilder.hpp"