diff --git a/README.md b/README.md
index cb7e85a31..d87e95cf2 100644
--- a/README.md
+++ b/README.md
@@ -1634,4 +1634,6 @@ Note that during the `ctest` stage, several JSON test files are downloaded from
 
 In case you have downloaded the library rather than checked out the code via Git, test `cmake_fetch_content_configure`. Please execute `ctest -LE git_required` to skip these tests. See [issue #2189](https://github.com/nlohmann/json/issues/2189) for more information.
 
+Some tests change the installed files and hence make the whole process not reproducible. Please execute `ctest -LE not_reproducible` to skip these tests. See [issue #2324](https://github.com/nlohmann/json/issues/2324) for more information.
+
 As Intel compilers use unsafe floating point optimization by default, the unit tests may fail. Use flag [`/fp:precise`](https://software.intel.com/content/www/us/en/develop/documentation/cpp-compiler-developer-guide-and-reference/top/compiler-reference/compiler-options/compiler-option-details/floating-point-options/fp-model-fp.html) then.
diff --git a/doc/Doxyfile b/doc/Doxyfile
index 9884f959b..45ca8822b 100644
--- a/doc/Doxyfile
+++ b/doc/Doxyfile
@@ -1,4 +1,4 @@
-# Doxyfile 1.8.19
+# Doxyfile 1.9.0
 
 #---------------------------------------------------------------------------
 # Project related configuration options
@@ -26,6 +26,7 @@ JAVADOC_AUTOBRIEF      = NO
 JAVADOC_BANNER         = NO
 QT_AUTOBRIEF           = NO
 MULTILINE_CPP_IS_BRIEF = NO
+PYTHON_DOCSTRING       = YES
 INHERIT_DOCS           = YES
 SEPARATE_MEMBER_PAGES  = YES
 TAB_SIZE               = 4
@@ -54,6 +55,7 @@ INLINE_GROUPED_CLASSES = NO
 INLINE_SIMPLE_STRUCTS  = NO
 TYPEDEF_HIDES_STRUCT   = NO
 LOOKUP_CACHE_SIZE      = 0
+NUM_PROC_THREADS       = 1
 #---------------------------------------------------------------------------
 # Build related configuration options
 #---------------------------------------------------------------------------
@@ -65,6 +67,7 @@ EXTRACT_STATIC         = YES
 EXTRACT_LOCAL_CLASSES  = YES
 EXTRACT_LOCAL_METHODS  = YES
 EXTRACT_ANON_NSPACES   = YES
+RESOLVE_UNNAMED_PARAMS = YES
 HIDE_UNDOC_MEMBERS     = NO
 HIDE_UNDOC_CLASSES     = NO
 HIDE_FRIEND_COMPOUNDS  = NO
@@ -143,7 +146,6 @@ VERBATIM_HEADERS       = NO
 # Configuration options related to the alphabetical class index
 #---------------------------------------------------------------------------
 ALPHABETICAL_INDEX     = YES
-COLS_IN_ALPHA_INDEX    = 5
 IGNORE_PREFIX          =
 #---------------------------------------------------------------------------
 # Configuration options related to the HTML output
@@ -307,6 +309,8 @@ COLLABORATION_GRAPH    = NO
 GROUP_GRAPHS           = YES
 UML_LOOK               = YES
 UML_LIMIT_NUM_FIELDS   = 10
+DOT_UML_DETAILS        = NO
+DOT_WRAP_THRESHOLD     = 17
 TEMPLATE_RELATIONS     = NO
 INCLUDE_GRAPH          = NO
 INCLUDED_BY_GRAPH      = NO
diff --git a/test/cmake_add_subdirectory/CMakeLists.txt b/test/cmake_add_subdirectory/CMakeLists.txt
index 4fa9eb88c..21c736a7b 100644
--- a/test/cmake_add_subdirectory/CMakeLists.txt
+++ b/test/cmake_add_subdirectory/CMakeLists.txt
@@ -10,7 +10,9 @@ add_test(NAME cmake_add_subdirectory_build
 )
 set_tests_properties(cmake_add_subdirectory_configure PROPERTIES
   FIXTURES_SETUP cmake_add_subdirectory
+  LABELS not_reproducible
 )
 set_tests_properties(cmake_add_subdirectory_build PROPERTIES
   FIXTURES_REQUIRED cmake_add_subdirectory
+  LABELS not_reproducible
 )
diff --git a/test/cmake_fetch_content/CMakeLists.txt b/test/cmake_fetch_content/CMakeLists.txt
index 0b0d9f65e..f850b8bd7 100644
--- a/test/cmake_fetch_content/CMakeLists.txt
+++ b/test/cmake_fetch_content/CMakeLists.txt
@@ -12,9 +12,11 @@ if (${CMAKE_VERSION} VERSION_GREATER "3.11.0")
   set_tests_properties(cmake_fetch_content_configure PROPERTIES
     FIXTURES_SETUP cmake_fetch_content
     LABELS git_required
+    LABELS not_reproducible
   )
   set_tests_properties(cmake_fetch_content_build PROPERTIES
     FIXTURES_REQUIRED cmake_fetch_content
     LABELS git_required
+    LABELS not_reproducible
   )
 endif()
diff --git a/test/cmake_import/CMakeLists.txt b/test/cmake_import/CMakeLists.txt
index af3c891cc..13290b2e3 100644
--- a/test/cmake_import/CMakeLists.txt
+++ b/test/cmake_import/CMakeLists.txt
@@ -11,7 +11,9 @@ add_test(NAME cmake_import_build
 )
 set_tests_properties(cmake_import_configure PROPERTIES
   FIXTURES_SETUP cmake_import
+  LABELS not_reproducible
 )
 set_tests_properties(cmake_import_build PROPERTIES
   FIXTURES_REQUIRED cmake_import
+  LABELS not_reproducible
 )
diff --git a/test/cmake_import_minver/CMakeLists.txt b/test/cmake_import_minver/CMakeLists.txt
index d1a107214..6d8db4399 100644
--- a/test/cmake_import_minver/CMakeLists.txt
+++ b/test/cmake_import_minver/CMakeLists.txt
@@ -11,7 +11,9 @@ add_test(NAME cmake_import_minver_build
 )
 set_tests_properties(cmake_import_minver_configure PROPERTIES
   FIXTURES_SETUP cmake_import_minver
+  LABELS not_reproducible
 )
 set_tests_properties(cmake_import_minver_build PROPERTIES
   FIXTURES_REQUIRED cmake_import_minver
+  LABELS not_reproducible
 )
diff --git a/test/cmake_target_include_directories/CMakeLists.txt b/test/cmake_target_include_directories/CMakeLists.txt
index da738ea4f..0a324cb92 100644
--- a/test/cmake_target_include_directories/CMakeLists.txt
+++ b/test/cmake_target_include_directories/CMakeLists.txt
@@ -10,7 +10,9 @@ add_test(NAME cmake_target_include_directories_build
 )
 set_tests_properties(cmake_target_include_directories_configure PROPERTIES
     FIXTURES_SETUP cmake_target_include_directories
+    LABELS not_reproducible
 )
 set_tests_properties(cmake_target_include_directories_build PROPERTIES
     FIXTURES_REQUIRED cmake_target_include_directories
+    LABELS not_reproducible
 )