diff --git a/jbmc/src/java_bytecode/java_class_loader_base.cpp b/jbmc/src/java_bytecode/java_class_loader_base.cpp
index 5a998bc4d636..2c3952719106 100644
--- a/jbmc/src/java_bytecode/java_class_loader_base.cpp
+++ b/jbmc/src/java_bytecode/java_class_loader_base.cpp
@@ -8,15 +8,15 @@ Author: Daniel Kroening, kroening@kroening.com
 
 #include "java_class_loader_base.h"
 
-#include "jar_file.h"
-#include "java_bytecode_parse_tree.h"
-#include "java_bytecode_parser.h"
-
-#include <util/file_util.h>
 #include <util/message.h>
 #include <util/prefix.h>
 #include <util/suffix.h>
 
+#include "jar_file.h"
+#include "java_bytecode_parse_tree.h"
+#include "java_bytecode_parser.h"
+
+#include <filesystem>
 #include <fstream>
 
 void java_class_loader_baset::add_classpath_entry(
@@ -40,7 +40,7 @@ void java_class_loader_baset::add_classpath_entry(
   }
   else
   {
-    if(is_directory(path))
+    if(std::filesystem::is_directory(path))
     {
       classpath_entries.push_back(
         classpath_entryt(classpath_entryt::DIRECTORY, path));
@@ -197,7 +197,8 @@ java_class_loader_baset::get_class_from_directory(
 {
   // Look in the given directory
   const std::string class_file = class_name_to_os_file(class_name);
-  const std::string full_path = concat_dir_file(path, class_file);
+  const std::string full_path =
+    std::filesystem::path(path).append(class_file).string();
 
   if(std::ifstream(full_path))
   {
diff --git a/jbmc/unit/java-testing-utils/load_java_class.cpp b/jbmc/unit/java-testing-utils/load_java_class.cpp
index e1f1fcf787b4..b8568719dc5b 100644
--- a/jbmc/unit/java-testing-utils/load_java_class.cpp
+++ b/jbmc/unit/java-testing-utils/load_java_class.cpp
@@ -8,19 +8,18 @@ Author: Diffblue Ltd.
 
 #include "load_java_class.h"
 
-#include <iostream>
-#include <testing-utils/free_form_cmdline.h>
-#include <testing-utils/message.h>
-#include <testing-utils/use_catch.h>
-
 #include <util/config.h>
 #include <util/options.h>
 #include <util/suffix.h>
 
+#include <java_bytecode/java_bytecode_language.h>
 #include <java_bytecode/lazy_goto_model.h>
+#include <testing-utils/free_form_cmdline.h>
+#include <testing-utils/message.h>
+#include <testing-utils/use_catch.h>
 
-#include <java_bytecode/java_bytecode_language.h>
-#include <util/file_util.h>
+#include <filesystem>
+#include <iostream>
 
 /// Go through the process of loading, type-checking and finalising loading a
 /// specific class file to build the symbol table. The functions are converted
@@ -149,7 +148,7 @@ goto_modelt load_goto_model_from_java_class(
   // Log the working directory to help people identify the common error
   // of wrong working directory (should be the `unit` directory when running
   // the unit tests).
-  std::string path = get_current_working_directory();
+  std::string path = std::filesystem::current_path().string();
   INFO("Working directory: " << path);
 
   // if this fails it indicates the class was not loaded
diff --git a/src/goto-analyzer/unreachable_instructions.cpp b/src/goto-analyzer/unreachable_instructions.cpp
index 6ff7822bed79..5fc03e49f917 100644
--- a/src/goto-analyzer/unreachable_instructions.cpp
+++ b/src/goto-analyzer/unreachable_instructions.cpp
@@ -13,7 +13,6 @@ Date: April 2016
 
 #include "unreachable_instructions.h"
 
-#include <util/file_util.h>
 #include <util/json_irep.h>
 #include <util/options.h>
 #include <util/xml.h>
@@ -23,6 +22,8 @@ Date: April 2016
 #include <analyses/ai.h>
 #include <analyses/cfg_dominators.h>
 
+#include <filesystem>
+
 typedef std::map<unsigned, goto_programt::const_targett> dead_mapt;
 
 static void unreachable_instructions(
@@ -106,9 +107,10 @@ file_name_string_opt(const source_locationt &source_location)
   if(source_location.get_file().empty())
     return {};
 
-  return concat_dir_file(
-    id2string(source_location.get_working_directory()),
-    id2string(source_location.get_file()));
+  return std::filesystem::path(
+           id2string(source_location.get_working_directory()))
+    .append(id2string(source_location.get_file()))
+    .string();
 }
 
 static void add_to_json(
diff --git a/src/goto-cc/as_mode.cpp b/src/goto-cc/as_mode.cpp
index d811a757bc23..fee687b2a9ee 100644
--- a/src/goto-cc/as_mode.cpp
+++ b/src/goto-cc/as_mode.cpp
@@ -21,7 +21,6 @@ Author: Michael Tautschnig
 
 #include <util/cmdline.h>
 #include <util/config.h>
-#include <util/file_util.h>
 #include <util/get_base_name.h>
 #include <util/run.h>
 #include <util/tempdir.h>
@@ -31,6 +30,7 @@ Author: Michael Tautschnig
 #include "goto_cc_cmdline.h"
 #include "hybrid_binary.h"
 
+#include <filesystem>
 #include <fstream> // IWYU pragma: keep
 #include <iostream>
 
@@ -303,9 +303,9 @@ int as_modet::as_hybrid_binary(const compilet &compiler)
   std::string saved = output_file + ".goto-cc-saved";
   try
   {
-    file_rename(output_file, saved);
+    std::filesystem::rename(output_file, saved);
   }
-  catch(const cprover_exception_baset &e)
+  catch(const std::filesystem::filesystem_error &e)
   {
     log.error() << "Rename failed: " << e.what() << messaget::eom;
     return 1;
diff --git a/src/goto-cc/compile.cpp b/src/goto-cc/compile.cpp
index 7823142a6b76..54623f731350 100644
--- a/src/goto-cc/compile.cpp
+++ b/src/goto-cc/compile.cpp
@@ -15,7 +15,6 @@ Date: June 2006
 
 #include <util/cmdline.h>
 #include <util/config.h>
-#include <util/file_util.h>
 #include <util/get_base_name.h>
 #include <util/prefix.h>
 #include <util/run.h>
@@ -39,6 +38,7 @@ Date: June 2006
 #include <linking/static_lifetime_init.h>
 
 #include <cstring>
+#include <filesystem>
 #include <fstream>
 #include <iostream>
 
@@ -217,11 +217,14 @@ bool compilet::add_files_from_archive(
     tstr = get_temporary_directory("goto-cc.XXXXXX");
 
     tmp_dirs.push_back(tstr);
-    set_current_path(tmp_dirs.back());
+    std::filesystem::current_path(tmp_dirs.back());
 
     // unpack now
-    int ret =
-      run("ar", {"ar", "x", concat_dir_file(working_directory, file_name)});
+    int ret = run(
+      "ar",
+      {"ar",
+       "x",
+       std::filesystem::path(working_directory).append(file_name).string()});
     if(ret != 0)
     {
       log.error() << "Failed to extract archive " << file_name << messaget::eom;
@@ -233,7 +236,9 @@ bool compilet::add_files_from_archive(
   temporary_filet tmp_file_out("", "");
   int ret = run(
     "ar",
-    {"ar", "t", concat_dir_file(working_directory, file_name)},
+    {"ar",
+     "t",
+     std::filesystem::path(working_directory).append(file_name).string()},
     "",
     tmp_file_out(),
     "");
@@ -248,7 +253,7 @@ bool compilet::add_files_from_archive(
 
   while(!in.fail() && std::getline(in, line))
   {
-    std::string t = concat_dir_file(tstr, line);
+    std::string t = std::filesystem::path(tstr).append(line).string();
 
     if(is_goto_binary(t, log.get_message_handler()))
       object_files.push_back(t);
@@ -258,7 +263,7 @@ bool compilet::add_files_from_archive(
   }
 
   if(!thin_archive)
-    set_current_path(working_directory);
+    std::filesystem::current_path(working_directory);
 
   return false;
 }
@@ -272,7 +277,8 @@ bool compilet::find_library(const std::string &name)
 
   for(const auto &library_path : library_paths)
   {
-    library_file_name = concat_dir_file(library_path, "lib" + name + ".a");
+    library_file_name =
+      std::filesystem::path(library_path).append("lib" + name + ".a").string();
 
     std::ifstream in(library_file_name);
 
@@ -280,7 +286,9 @@ bool compilet::find_library(const std::string &name)
       return !add_input_file(library_file_name);
     else
     {
-      library_file_name = concat_dir_file(library_path, "lib" + name + ".so");
+      library_file_name = std::filesystem::path(library_path)
+                            .append("lib" + name + ".so")
+                            .string();
 
       switch(detect_file_type(library_file_name, log.get_message_handler()))
       {
@@ -409,7 +417,11 @@ optionalt<symbol_tablet> compilet::compile()
           get_base_name(file_name, true) + "." + object_file_extension;
 
         if(!output_directory_object.empty())
-          cfn = concat_dir_file(output_directory_object, file_name_with_obj_ext);
+        {
+          cfn = std::filesystem::path(output_directory_object)
+                  .append(file_name_with_obj_ext)
+                  .string();
+        }
         else
           cfn = file_name_with_obj_ext;
       }
@@ -648,7 +660,7 @@ compilet::compilet(cmdlinet &_cmdline, message_handlert &mh, bool Werror)
   mode=COMPILE_LINK_EXECUTABLE;
   echo_file_name=false;
   wrote_object=false;
-  working_directory=get_current_working_directory();
+  working_directory = std::filesystem::current_path().string();
 
   if(cmdline.isset("export-function-local-symbols"))
   {
@@ -665,7 +677,7 @@ compilet::~compilet()
   // clean up temp dirs
 
   for(const auto &dir : tmp_dirs)
-    delete_directory(dir);
+    std::filesystem::remove_all(dir);
 }
 
 std::size_t compilet::function_body_count(const goto_functionst &functions)
diff --git a/src/goto-cc/gcc_mode.cpp b/src/goto-cc/gcc_mode.cpp
index 5459ad361c1f..0c9d6d50cbf5 100644
--- a/src/goto-cc/gcc_mode.cpp
+++ b/src/goto-cc/gcc_mode.cpp
@@ -21,7 +21,6 @@ Author: CM Wintersteiger, 2006
 
 #include <util/cmdline.h>
 #include <util/config.h>
-#include <util/file_util.h>
 #include <util/get_base_name.h>
 #include <util/invariant.h>
 #include <util/prefix.h>
@@ -35,6 +34,7 @@ Author: CM Wintersteiger, 2006
 #include "hybrid_binary.h"
 #include "linker_script_merge.h"
 
+#include <filesystem>
 #include <fstream> // IWYU pragma: keep
 #include <iostream>
 #include <numeric>
@@ -1006,9 +1006,9 @@ int gcc_modet::gcc_hybrid_binary(compilet &compiler)
 
     try
     {
-      file_rename(*it, bin_name);
+      std::filesystem::rename(*it, bin_name);
     }
-    catch(const cprover_exception_baset &e)
+    catch(const std::filesystem::filesystem_error &e)
     {
       log.error() << "Rename failed: " << e.what() << messaget::eom;
       return 1;
diff --git a/src/goto-cc/hybrid_binary.cpp b/src/goto-cc/hybrid_binary.cpp
index 745fa3cd478a..434c08c34d3b 100644
--- a/src/goto-cc/hybrid_binary.cpp
+++ b/src/goto-cc/hybrid_binary.cpp
@@ -11,12 +11,12 @@ Author: Michael Tautschnig, 2018
 
 #include "hybrid_binary.h"
 
-#include <util/file_util.h>
 #include <util/message.h>
 #include <util/run.h>
 #include <util/suffix.h>
 
 #include <cstring>
+#include <filesystem>
 
 #if defined(__APPLE__)
 #  include <sys/stat.h>
@@ -80,7 +80,7 @@ int hybrid_binary(
   }
 
   // delete the goto binary
-  bool remove_result = file_remove(goto_binary_file);
+  bool remove_result = std::filesystem::remove(goto_binary_file);
   if(!remove_result)
   {
     message.error() << "Remove failed: " << std::strerror(errno)
@@ -140,7 +140,7 @@ int hybrid_binary(
   }
 
   // delete the goto binary
-  bool remove_result = file_remove(goto_binary_file);
+  bool remove_result = std::filesystem::remove(goto_binary_file);
   if(!remove_result)
   {
     message.error() << "Remove failed: " << std::strerror(errno)
diff --git a/src/goto-cc/ld_mode.cpp b/src/goto-cc/ld_mode.cpp
index b443a4ef033a..bee843fa3fa6 100644
--- a/src/goto-cc/ld_mode.cpp
+++ b/src/goto-cc/ld_mode.cpp
@@ -19,13 +19,8 @@ Author: CM Wintersteiger, 2006
 #include <sysexits.h>
 #endif
 
-#include <cstring>
-#include <fstream>
-#include <iostream>
-
 #include <util/cmdline.h>
 #include <util/config.h>
-#include <util/file_util.h>
 #include <util/invariant.h>
 #include <util/run.h>
 
@@ -34,6 +29,11 @@ Author: CM Wintersteiger, 2006
 #include "hybrid_binary.h"
 #include "linker_script_merge.h"
 
+#include <cstring>
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+
 static std::string
 linker_name(const cmdlinet &cmdline, const std::string &base_name)
 {
@@ -183,9 +183,9 @@ int ld_modet::ld_hybrid_binary(
 
   try
   {
-    file_rename(output_file, goto_binary);
+    std::filesystem::rename(output_file, goto_binary);
   }
-  catch(const cprover_exception_baset &e)
+  catch(const std::filesystem::filesystem_error &e)
   {
     log.error() << "Rename failed: " << e.what() << messaget::eom;
     return 1;
diff --git a/src/goto-cc/ms_cl_mode.cpp b/src/goto-cc/ms_cl_mode.cpp
index ea9193a800b9..bbc78a165b1f 100644
--- a/src/goto-cc/ms_cl_mode.cpp
+++ b/src/goto-cc/ms_cl_mode.cpp
@@ -19,16 +19,16 @@ Author: CM Wintersteiger, 2006
 #include <sysexits.h>
 #endif
 
-#include <iostream>
-
 #include <util/config.h>
-#include <util/file_util.h>
 #include <util/get_base_name.h>
 #include <util/message.h>
 
 #include "compile.h"
 #include "ms_cl_version.h"
 
+#include <filesystem>
+#include <iostream>
+
 static bool has_directory_suffix(const std::string &path)
 {
   // MS CL decides whether a parameter is a directory on the
@@ -128,7 +128,7 @@ int ms_cl_modet::doit()
     {
       compiler.output_directory_object = Fo_value;
 
-      if(!is_directory(Fo_value))
+      if(!std::filesystem::is_directory(Fo_value))
         log.warning() << "not a directory: " << Fo_value << messaget::eom;
     }
     else
@@ -154,7 +154,7 @@ int ms_cl_modet::doit()
       has_directory_suffix(compiler.output_file_executable) &&
       cmdline.args.size() >= 1)
     {
-      if(!is_directory(compiler.output_file_executable))
+      if(!std::filesystem::is_directory(compiler.output_file_executable))
       {
         log.warning() << "not a directory: " << compiler.output_file_executable
                       << messaget::eom;
diff --git a/src/goto-instrument/count_eloc.cpp b/src/goto-instrument/count_eloc.cpp
index 51bf3e825d4c..a2185e2f9ab6 100644
--- a/src/goto-instrument/count_eloc.cpp
+++ b/src/goto-instrument/count_eloc.cpp
@@ -13,10 +13,6 @@ Date: December 2012
 
 #include "count_eloc.h"
 
-#include <iostream>
-#include <unordered_set>
-
-#include <util/file_util.h>
 #include <util/pointer_expr.h>
 #include <util/pointer_offset_size.h>
 #include <util/prefix.h>
@@ -26,6 +22,10 @@ Date: December 2012
 
 #include <linking/static_lifetime_init.h>
 
+#include <filesystem>
+#include <iostream>
+#include <unordered_set>
+
 typedef std::unordered_set<irep_idt> linest;
 typedef std::unordered_map<irep_idt, linest> filest;
 typedef std::unordered_map<irep_idt, filest> working_dirst;
@@ -75,7 +75,8 @@ void list_eloc(const goto_modelt &goto_model)
     {
       std::string file=id2string(lines.first);
       if(!files.first.empty())
-        file=concat_dir_file(id2string(files.first), file);
+        file =
+          std::filesystem::path(id2string(files.first)).append(file).string();
 
       for(const irep_idt &line : lines.second)
         std::cout << file << ':' << line << '\n';
diff --git a/src/util/Makefile b/src/util/Makefile
index 30452e2e3029..1e33ebc73db6 100644
--- a/src/util/Makefile
+++ b/src/util/Makefile
@@ -17,7 +17,6 @@ SRC = arith_tools.cpp \
       expr_initializer.cpp \
       expr_util.cpp \
       exception_utils.cpp \
-      file_util.cpp \
       find_macros.cpp \
       find_symbols.cpp \
       fixedbv.cpp \
diff --git a/src/util/file_util.cpp b/src/util/file_util.cpp
deleted file mode 100644
index d1cd3378a052..000000000000
--- a/src/util/file_util.cpp
+++ /dev/null
@@ -1,274 +0,0 @@
-/*******************************************************************\
-
-Module: File Utilities
-
-Author:
-
-Date: January 2012
-
-\*******************************************************************/
-
-/// \file
-/// File Utilities
-
-#include "file_util.h"
-
-#include "exception_utils.h"
-
-#include <cerrno>
-#include <cstring>
-
-#if defined(__linux__) || \
-    defined(__FreeBSD_kernel__) || \
-    defined(__GNU__) || \
-    defined(__unix__) || \
-    defined(__CYGWIN__) || \
-    defined(__MACH__)
-#include <sys/stat.h>
-#include <unistd.h>
-#include <dirent.h>
-#include <cstdlib>
-#include <cstdio>
-#endif
-
-#ifdef _WIN32
-#include <util/pragma_push.def>
-#ifdef _MSC_VER
-#pragma warning(disable:4668)
-  // using #if/#elif on undefined macro
-#pragma warning(disable : 5039)
-// pointer or reference to potentially throwing function passed to extern C
-#endif
-#include <io.h>
-#include <windows.h>
-#include <direct.h>
-#include <util/unicode.h>
-#define chdir _chdir
-#include <util/pragma_pop.def>
-#endif
-
-/// \return current working directory
-std::string get_current_working_directory()
-{
-#ifndef _WIN32
-  errno=0;
-  char *wd=realpath(".", nullptr);
-
-  if(wd == nullptr)
-    throw system_exceptiont(
-      std::string("realpath failed: ") + std::strerror(errno));
-
-  std::string working_directory=wd;
-  free(wd);
-#else
-  TCHAR buffer[4096];
-  DWORD retval=GetCurrentDirectory(4096, buffer);
-  if(retval == 0)
-    throw system_exceptiont("failed to get current directory of process");
-
-#  ifdef UNICODE
-  std::string working_directory(narrow(buffer));
-#  else
-  std::string working_directory(buffer);
-#  endif
-
-#endif
-
-  return working_directory;
-}
-
-/// Set working directory.
-/// \param path: New working directory to change to
-void set_current_path(const std::string &path)
-{
-  if(chdir(path.c_str()) != 0)
-    throw system_exceptiont(
-      std::string("chdir failed: ") + std::strerror(errno));
-}
-
-/// deletes all files in 'path' and then the directory itself
-#ifdef _WIN32
-
-void delete_directory_utf16(const std::wstring &path)
-{
-  std::wstring pattern=path + L"\\*";
-  // NOLINTNEXTLINE(readability/identifiers)
-  struct _wfinddata_t info;
-  intptr_t hFile=_wfindfirst(pattern.c_str(), &info);
-  if(hFile!=-1)
-  {
-    do
-    {
-      if(wcscmp(info.name, L".")==0 || wcscmp(info.name, L"..")==0)
-        continue;
-      std::wstring sub_path=path+L"\\"+info.name;
-      if(info.attrib & _A_SUBDIR)
-        delete_directory_utf16(sub_path);
-      else
-        DeleteFileW(sub_path.c_str());
-    }
-    while(_wfindnext(hFile, &info)==0);
-    _findclose(hFile);
-    RemoveDirectoryW(path.c_str());
-  }
-}
-
-#endif
-
-void delete_directory(const std::string &path)
-{
-#ifdef _WIN32
-  delete_directory_utf16(utf8_to_utf16_native_endian(path));
-#else
-  DIR *dir=opendir(path.c_str());
-  if(dir!=nullptr)
-  {
-    struct dirent *ent;
-    while((ent=readdir(dir))!=nullptr)
-    {
-      // Needed for Alpine Linux
-      if(strcmp(ent->d_name, ".")==0 || strcmp(ent->d_name, "..")==0)
-        continue;
-
-      std::string sub_path=path+"/"+ent->d_name;
-
-      struct stat stbuf;
-      int result=stat(sub_path.c_str(), &stbuf);
-      if(result!=0)
-        throw system_exceptiont(
-          std::string("Stat failed: ") + std::strerror(errno));
-
-      if(S_ISDIR(stbuf.st_mode))
-        delete_directory(sub_path);
-      else
-      {
-        result=remove(sub_path.c_str());
-        if(result!=0)
-          throw system_exceptiont(
-            std::string("Remove failed: ") + std::strerror(errno));
-      }
-    }
-    closedir(dir);
-  }
-  rmdir(path.c_str());
-#endif
-}
-
-/// \par parameters: directory name and file name
-/// \return concatenation of directory and file, if the file path is relative
-std::string concat_dir_file(
-  const std::string &directory,
-  const std::string &file_name)
-{
-#ifdef _WIN32
-  if(
-    file_name.size() > 1 && file_name[0] != '/' && file_name[0] != '\\' &&
-    file_name[1] == ':')
-  {
-    return file_name;
-  }
-  else if(
-    !directory.empty() && (directory.back() == '/' || directory.back() == '\\'))
-  {
-    return directory + file_name;
-  }
-  else
-    return directory + '\\' + file_name;
-#else
-  if(!file_name.empty() && file_name[0] == '/')
-    return file_name;
-  else if(!directory.empty() && directory.back() == '/')
-    return directory + file_name;
-  else
-    return directory + '/' + file_name;
-#endif
-}
-
-bool is_directory(const std::string &path)
-{
-  if(path.empty())
-    return false;
-
-#ifdef _WIN32
-
-  auto attributes = ::GetFileAttributesW(widen(path).c_str());
-  if (attributes == INVALID_FILE_ATTRIBUTES)
-    return false;
-  else
-    return (attributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
-
-#else
-
-  struct stat buf;
-
-  if(stat(path.c_str(), &buf)!=0)
-    return false;
-  else
-    return (buf.st_mode & S_IFDIR) != 0;
-
-#endif
-}
-
-bool create_directory(const std::string &path)
-{
-#ifdef _WIN32
-  return _mkdir(path.c_str()) == 0;
-#else
-  // the umask matches what std::filesystem::create_directory does
-  return mkdir(path.c_str(), 0777) == 0;
-#endif
-}
-
-bool file_exists(const std::string &path)
-{
-#ifdef _WIN32
-  return _waccess(utf8_to_utf16_native_endian(path).c_str(), 0) == 0;
-#else
-  return access(path.c_str(), F_OK) == 0;
-#endif
-}
-
-bool file_remove(const std::string &path)
-{
-#ifdef _WIN32
-  return _wunlink(utf8_to_utf16_native_endian(path).c_str()) == 0;
-#else
-  return unlink(path.c_str()) == 0;
-#endif
-}
-
-void file_rename(const std::string &old_path, const std::string &new_path)
-{
-#ifdef _WIN32
-  if(is_directory(old_path))
-  {
-    // rename() only renames directories, but does not move them.
-    // MoveFile is not atomic.
-    auto MoveFile_result =
-      MoveFileW(widen(old_path).c_str(), widen(new_path).c_str());
-
-    if(MoveFile_result == 0)
-      throw system_exceptiont("MoveFileW failed");
-  }
-  else
-  {
-    // C++17 requires this to be atomic.
-    // MoveFile, MoveFileEx() or rename() do not guarantee this.
-    // Any existing file at new_path is to be overwritten.
-    // rename() does not do so on Windows.
-    auto MoveFileEx_result = MoveFileExW(
-      widen(old_path).c_str(),
-      widen(new_path).c_str(),
-      MOVEFILE_REPLACE_EXISTING); // flags
-
-    if(MoveFileEx_result == 0)
-      throw system_exceptiont("MoveFileExW failed");
-  }
-#else
-  int rename_result = rename(old_path.c_str(), new_path.c_str());
-
-  if(rename_result != 0)
-    throw system_exceptiont(
-      std::string("rename failed: ") + std::strerror(errno));
-#endif
-}
diff --git a/src/util/file_util.h b/src/util/file_util.h
deleted file mode 100644
index 0e749a889e03..000000000000
--- a/src/util/file_util.h
+++ /dev/null
@@ -1,50 +0,0 @@
-/*******************************************************************\
-
-Module:
-
-Author: Daniel Kroening, kroening@kroening.com
-
-\*******************************************************************/
-
-
-#ifndef CPROVER_UTIL_FILE_UTIL_H
-#define CPROVER_UTIL_FILE_UTIL_H
-
-#include <string>
-
-// C++17 will allow us to use std::filesystem::path::remove_all
-void delete_directory(const std::string &path);
-
-// C++17 will allow us to use std::filesystem::current_path (for both get and
-// set)
-std::string get_current_working_directory();
-void set_current_path(const std::string &path);
-
-// C++17 will allow us to use std::filesystem::path(dir).append(file)
-std::string concat_dir_file(const std::string &directory,
-                            const std::string &file_name);
-
-// C++17 will allow us to use std::filesystem::is_directory
-bool is_directory(const std::string &path);
-
-/// Create a directory with given path
-/// C++17 will allow us to use std::filesystem::create_directory
-/// \return true iff the directory was created
-bool create_directory(const std::string &path);
-
-/// Check whether file with given path exists.
-/// C++17 will allow us to use std::filesystem::directory_entry(file).exists()
-/// \return true iff the file exists
-bool file_exists(const std::string &path);
-
-// Delete a file with given path
-/// C++17 will allow us to use std::filesystem::remove
-/// \return true if the file was deleted, false if it did not exist
-bool file_remove(const std::string &path);
-
-/// Rename a file.
-/// C++17 will allow us to use std::filesystem::rename
-/// Throws an exception on failure.
-void file_rename(const std::string &old_path, const std::string &new_path);
-
-#endif // CPROVER_UTIL_FILE_UTIL_H
diff --git a/src/util/parser.h b/src/util/parser.h
index 9fc1e3c577dd..70a796ec4a91 100644
--- a/src/util/parser.h
+++ b/src/util/parser.h
@@ -12,14 +12,14 @@ Author: Daniel Kroening, kroening@kroening.com
 #ifndef CPROVER_UTIL_PARSER_H
 #define CPROVER_UTIL_PARSER_H
 
+#include "expr.h"
+#include "message.h"
+
+#include <filesystem>
 #include <iosfwd>
 #include <string>
 #include <vector>
 
-#include "expr.h"
-#include "message.h"
-#include "file_util.h"
-
 class parsert
 {
 public:
@@ -86,7 +86,7 @@ class parsert
   {
     source_location.set_file(file);
     source_location.set_working_directory(
-      get_current_working_directory());
+      std::filesystem::current_path().string());
   }
 
   irep_idt get_file() const
diff --git a/src/util/source_location.cpp b/src/util/source_location.cpp
index 58897b858da5..44656e09e4ca 100644
--- a/src/util/source_location.cpp
+++ b/src/util/source_location.cpp
@@ -8,11 +8,11 @@ Author: Daniel Kroening, kroening@kroening.com
 
 #include "source_location.h"
 
-#include <ostream>
-
-#include "file_util.h"
 #include "prefix.h"
 
+#include <filesystem>
+#include <ostream>
+
 bool source_locationt::is_built_in(const std::string &s)
 {
   std::string built_in1 = "<built-in-"; // "<built-in-additions>";
@@ -37,8 +37,11 @@ std::string source_locationt::as_string(bool print_cwd) const
       dest+=' ';
     dest+="file ";
     if(print_cwd)
-      dest+=
-        concat_dir_file(id2string(get_working_directory()), id2string(file));
+    {
+      dest += std::filesystem::path(id2string(get_working_directory()))
+                .append(id2string(file))
+                .string();
+    }
     else
       dest+=id2string(file);
   }
@@ -89,7 +92,9 @@ optionalt<std::string> source_locationt::full_path() const
   if(file.empty() || is_built_in(file))
     return {};
 
-  return concat_dir_file(id2string(get_working_directory()), file);
+  return std::filesystem::path(id2string(get_working_directory()))
+    .append(file)
+    .string();
 }
 
 std::ostream &operator << (
diff --git a/src/util/tempdir.cpp b/src/util/tempdir.cpp
index b8b0a0fe78b5..c957bd3c1718 100644
--- a/src/util/tempdir.cpp
+++ b/src/util/tempdir.cpp
@@ -8,34 +8,23 @@ Author: CM Wintersteiger
 
 #include "tempdir.h"
 
-#ifdef _WIN32
-#include <util/pragma_push.def>
-#ifdef _MSC_VER
-#pragma warning(disable:4668)
-  // using #if/#elif on undefined macro
-#pragma warning(disable : 5039)
-// pointer or reference to potentially throwing function passed to extern C
-#endif
-#include <windows.h>
-#include <io.h>
-#include <direct.h>
-#include <util/pragma_pop.def>
-#endif
-
-#include <cstdlib>
-#include <cstring>
-#include <vector>
+#include <filesystem>
 
 // clang-format off
+#ifndef _WIN32
 #if defined(__FreeBSD_kernel__) || \
     defined(__CYGWIN__) || \
     defined(__MACH__)
 #include <unistd.h>
 #endif
+
+#include <cstdlib>
+#include <cstring>
+#include <vector>
+#endif
 // clang-format on
 
 #include "exception_utils.h"
-#include "file_util.h"
 
 std::string get_temporary_directory(const std::string &name_template)
 {
@@ -43,36 +32,14 @@ std::string get_temporary_directory(const std::string &name_template)
 
 #ifdef _WIN32
   (void)name_template; // unused parameter
-  DWORD dwBufSize = MAX_PATH + 1;
-  char lpPathBuffer[MAX_PATH + 1];
-  DWORD dwRetVal = GetTempPathA(dwBufSize, lpPathBuffer);
-
-  if(dwRetVal > dwBufSize || (dwRetVal == 0))
+  try
   {
-    throw system_exceptiont("Couldn't get temporary path");
+    result = std::filesystem::temp_directory_path().string();
   }
-
-  // GetTempFileNameA produces <path>\<pre><uuuu>.TMP
-  // where <pre> = "TLO"
-  // Thus, we must make the buffer 1+3+4+1+3=12 characters longer.
-
-  char t[MAX_PATH];
-  UINT uRetVal = GetTempFileNameA(lpPathBuffer, "TLO", 0, t);
-  if(uRetVal == 0)
+  catch(const std::filesystem::filesystem_error &)
   {
-    throw system_exceptiont(
-      std::string("Couldn't get new temporary file name in directory") +
-      lpPathBuffer);
-  }
-
-  unlink(t);
-  if(_mkdir(t) != 0)
-  {
-    throw system_exceptiont(
-      std::string("Couldn't create temporary directory at ") + t);
+    throw system_exceptiont("Failed to create temporary directory");
   }
-  result = std::string(t);
-
 #else
   std::string prefixed_name_template = "/tmp/";
   const char *TMPDIR_env = getenv("TMPDIR");
@@ -110,12 +77,12 @@ temp_dirt::temp_dirt(const std::string &name_template)
 
 std::string temp_dirt::operator()(const std::string &file)
 {
-  return concat_dir_file(path, file);
+  return std::filesystem::path(path).append(file).string();
 }
 
 void temp_dirt::clear()
 {
-  delete_directory(path);
+  std::filesystem::remove_all(path);
 }
 
 temp_dirt::~temp_dirt()
diff --git a/src/util/tempfile.cpp b/src/util/tempfile.cpp
index 278c115d8a55..ad0e6dec577a 100644
--- a/src/util/tempfile.cpp
+++ b/src/util/tempfile.cpp
@@ -33,9 +33,9 @@ Author: Daniel Kroening
 
 #include <cstdlib>
 #include <cstring>
+#include <filesystem>
 
 #include "exception_utils.h"
-#include "file_util.h"
 
 #if defined(__linux__) || \
     defined(__FreeBSD_kernel__) || \
@@ -145,5 +145,5 @@ std::string get_temporary_file(
 temporary_filet::~temporary_filet()
 {
   if(!name.empty())
-    file_remove(name);
+    std::filesystem::remove(name);
 }
diff --git a/unit/Makefile b/unit/Makefile
index de364726e36b..af2afbb02076 100644
--- a/unit/Makefile
+++ b/unit/Makefile
@@ -141,7 +141,6 @@ SRC += analyses/ai/ai.cpp \
        util/expr_initializer.cpp \
        util/expr.cpp \
        util/expr_iterator.cpp \
-       util/file_util.cpp \
        util/format.cpp \
        util/format_expr.cpp \
        util/format_number_range.cpp \
diff --git a/unit/util/file_util.cpp b/unit/util/file_util.cpp
deleted file mode 100644
index 93c03fcfa927..000000000000
--- a/unit/util/file_util.cpp
+++ /dev/null
@@ -1,72 +0,0 @@
-/*******************************************************************\
-
-Module: Unit tests for file_util.h
-
-Author: Daniel Kroening
-
-\*******************************************************************/
-
-#include <util/exception_utils.h> // IWYU pragma: keep
-#include <util/file_util.h>
-#include <util/tempdir.h>
-
-#include <testing-utils/use_catch.h>
-
-#ifdef _MSC_VER
-#  include <util/unicode.h>
-#endif
-
-#include <fstream>
-
-TEST_CASE("concat_dir_file functionality", "[core][util][file_util]")
-{
-  temp_dirt temp_dir("testXXXXXX");
-  const std::string path = concat_dir_file(temp_dir.path, "bla.txt");
-
-  REQUIRE(path.size() > temp_dir.path.size() + std::string("bla.txt").size());
-#ifdef _WIN32
-  REQUIRE(path.find('\\') != std::string::npos);
-#else
-  REQUIRE(path.find('/') != std::string::npos);
-#endif
-
-#ifdef _WIN32
-  const std::string qualified_path = "z:\\some\\path\\foo.txt";
-#else
-  const std::string qualified_path = "/some/path/foo.txt";
-#endif
-  const std::string path2 = concat_dir_file(temp_dir.path, qualified_path);
-  REQUIRE(path2 == qualified_path);
-}
-
-TEST_CASE("is_directory functionality", "[core][util][file_util]")
-{
-  temp_dirt temp_dir("testXXXXXX");
-
-#ifdef _MSC_VER
-  std::ofstream outfile(widen(temp_dir("file")));
-#else
-  std::ofstream outfile(temp_dir("file"));
-#endif
-
-  outfile.close();
-
-  REQUIRE(is_directory(temp_dir.path));
-  REQUIRE(is_directory(temp_dir.path+"/"));
-  REQUIRE(!is_directory(temp_dir("whatnot")));
-  REQUIRE(!is_directory(temp_dir("file")));
-  REQUIRE(!is_directory(""));
-}
-
-TEST_CASE("get/set working directory", "[core][util][file_util]")
-{
-  temp_dirt temp_dir("testXXXXXX");
-
-  std::string cwd = get_current_working_directory();
-  REQUIRE(cwd != temp_dir.path);
-  set_current_path(temp_dir.path);
-  REQUIRE(get_current_working_directory() == temp_dir.path);
-  REQUIRE_THROWS_AS(set_current_path("no-such-dir"), system_exceptiont);
-
-  set_current_path(cwd);
-}