diff --git a/include/dwarfs/util.h b/include/dwarfs/util.h
index a031a05e..a039bd23 100644
--- a/include/dwarfs/util.h
+++ b/include/dwarfs/util.h
@@ -24,12 +24,15 @@
 #include <chrono>
 #include <cstddef>
 #include <filesystem>
+#include <span>
 #include <string>
 
 #include "dwarfs/types.h"
 
 namespace dwarfs {
 
+struct iolayer;
+
 std::string time_with_unit(double sec);
 std::string size_with_unit(size_t size);
 size_t parse_size_with_unit(std::string const& str);
@@ -44,6 +47,10 @@ inline std::string u8string_to_string(std::u8string const& in) {
 }
 
 std::string sys_string_to_string(sys_string const& in);
+sys_string string_to_sys_string(std::string const& in);
+
+int call_sys_main_iolayer(std::span<char const*> args, iolayer const& iol,
+                          int (*main)(int, sys_char**, iolayer const&));
 
 size_t utf8_display_width(char const* p, size_t len);
 size_t utf8_display_width(std::string const& str);
diff --git a/include/dwarfs_tool_main.h b/include/dwarfs_tool_main.h
index 44a92c40..e263dfb1 100644
--- a/include/dwarfs_tool_main.h
+++ b/include/dwarfs_tool_main.h
@@ -22,6 +22,7 @@
 #pragma once
 
 #include <iosfwd>
+#include <span>
 
 #include "dwarfs/types.h"
 
@@ -35,18 +36,23 @@ namespace dwarfs {
 
 struct iolayer;
 
+int mkdwarfs_main(std::span<char const*> args, iolayer const& iol);
 int mkdwarfs_main(int argc, sys_char** argv, iolayer const& iol);
 int mkdwarfs_main(int argc, sys_char** argv);
 
+int dwarfsck_main(std::span<char const*> args, iolayer const& iol);
 int dwarfsck_main(int argc, sys_char** argv, iolayer const& iol);
 int dwarfsck_main(int argc, sys_char** argv);
 
+int dwarfsextract_main(std::span<char const*> args, iolayer const& iol);
 int dwarfsextract_main(int argc, sys_char** argv, iolayer const& iol);
 int dwarfsextract_main(int argc, sys_char** argv);
 
+int dwarfsbench_main(std::span<char const*> args, iolayer const& iol);
 int dwarfsbench_main(int argc, sys_char** argv, iolayer const& iol);
 int dwarfsbench_main(int argc, sys_char** argv);
 
+int dwarfs_main(std::span<char const*> args, iolayer const& iol);
 int dwarfs_main(int argc, sys_char** argv, iolayer const& iol);
 int dwarfs_main(int argc, sys_char** argv);
 
diff --git a/src/dwarfs/util.cpp b/src/dwarfs/util.cpp
index 65db4f21..72ee664a 100644
--- a/src/dwarfs/util.cpp
+++ b/src/dwarfs/util.cpp
@@ -136,6 +136,31 @@ std::string sys_string_to_string(sys_string const& in) {
 #endif
 }
 
+sys_string string_to_sys_string(std::string const& in) {
+#ifdef _WIN32
+  auto tmp = utf8::utf8to16(in);
+  sys_string rv(tmp.size(), 0);
+  std::transform(tmp.begin(), tmp.end(), rv.begin(),
+                 [](char16_t c) { return static_cast<sys_char>(c); });
+  return rv;
+#else
+  return in;
+#endif
+}
+
+int call_sys_main_iolayer(std::span<char const*> args, iolayer const& iol,
+                          int (*main)(int, sys_char**, iolayer const&)) {
+  std::vector<sys_string> argv;
+  std::vector<sys_char*> argv_ptrs;
+  argv.reserve(args.size());
+  argv_ptrs.reserve(args.size());
+  for (auto const& arg : args) {
+    argv.emplace_back(string_to_sys_string(arg));
+    argv_ptrs.emplace_back(argv.back().data());
+  }
+  return main(argv_ptrs.size(), argv_ptrs.data(), iol);
+}
+
 size_t utf8_display_width(char const* p, size_t len) {
   char const* const e = p + len;
   size_t rv = 0;
diff --git a/src/dwarfs_main.cpp b/src/dwarfs_main.cpp
index 3d8c5c56..47a4fc67 100644
--- a/src/dwarfs_main.cpp
+++ b/src/dwarfs_main.cpp
@@ -1389,4 +1389,8 @@ int dwarfs_main(int argc, sys_char** argv) {
   return dwarfs_main(argc, argv, iolayer::system_default());
 }
 
+int dwarfs_main(std::span<char const*> args, iolayer const& iol) {
+  return call_sys_main_iolayer(args, iol, dwarfs_main);
+}
+
 } // namespace dwarfs
diff --git a/src/dwarfsbench_main.cpp b/src/dwarfsbench_main.cpp
index 0482001b..178721b5 100644
--- a/src/dwarfsbench_main.cpp
+++ b/src/dwarfsbench_main.cpp
@@ -141,4 +141,8 @@ int dwarfsbench_main(int argc, sys_char** argv) {
   return dwarfsbench_main(argc, argv, iolayer::system_default());
 }
 
+int dwarfsbench_main(std::span<char const*> args, iolayer const& iol) {
+  return call_sys_main_iolayer(args, iol, dwarfsbench_main);
+}
+
 } // namespace dwarfs
diff --git a/src/dwarfsck_main.cpp b/src/dwarfsck_main.cpp
index 8409857b..b3c82733 100644
--- a/src/dwarfsck_main.cpp
+++ b/src/dwarfsck_main.cpp
@@ -208,4 +208,8 @@ int dwarfsck_main(int argc, sys_char** argv) {
   return dwarfsck_main(argc, argv, iolayer::system_default());
 }
 
+int dwarfsck_main(std::span<char const*> args, iolayer const& iol) {
+  return call_sys_main_iolayer(args, iol, dwarfsck_main);
+}
+
 } // namespace dwarfs
diff --git a/src/dwarfsextract_main.cpp b/src/dwarfsextract_main.cpp
index 02eb8dc5..8c5f6a82 100644
--- a/src/dwarfsextract_main.cpp
+++ b/src/dwarfsextract_main.cpp
@@ -201,4 +201,8 @@ int dwarfsextract_main(int argc, sys_char** argv) {
   return dwarfsextract_main(argc, argv, iolayer::system_default());
 }
 
+int dwarfsextract_main(std::span<char const*> args, iolayer const& iol) {
+  return call_sys_main_iolayer(args, iol, dwarfsextract_main);
+}
+
 } // namespace dwarfs
diff --git a/src/mkdwarfs_main.cpp b/src/mkdwarfs_main.cpp
index d7eae5d0..c01245eb 100644
--- a/src/mkdwarfs_main.cpp
+++ b/src/mkdwarfs_main.cpp
@@ -1289,4 +1289,8 @@ int mkdwarfs_main(int argc, sys_char** argv) {
   return mkdwarfs_main(argc, argv, iolayer::system_default());
 }
 
+int mkdwarfs_main(std::span<char const*> args, iolayer const& iol) {
+  return call_sys_main_iolayer(args, iol, mkdwarfs_main);
+}
+
 } // namespace dwarfs