diff --git a/Utilities/File.cpp b/Utilities/File.cpp
index d7f96e75dc..1e3dc38d87 100644
--- a/Utilities/File.cpp
+++ b/Utilities/File.cpp
@@ -794,7 +794,7 @@ fs::file::file(const std::string& path, bs_t<open_mode> mode)
 #ifdef _WIN32
 	DWORD access = 0;
 	if (test(mode & fs::read)) access |= GENERIC_READ;
-	if (test(mode & fs::write)) access |= test(mode & fs::append) ? FILE_APPEND_DATA : GENERIC_WRITE;
+	if (test(mode & fs::write)) access |= DELETE | (test(mode & fs::append) ? FILE_APPEND_DATA : GENERIC_WRITE);
 
 	DWORD disp = 0;
 	if (test(mode & fs::create))
@@ -814,8 +814,13 @@ fs::file::file(const std::string& path, bs_t<open_mode> mode)
 		disp = test(mode & fs::trunc) ? TRUNCATE_EXISTING : OPEN_EXISTING;
 	}
 
-	DWORD share = FILE_SHARE_READ;
-	if (!test(mode & fs::unshare))
+	DWORD share = 0;
+	if (!test(mode, fs::unread) || !test(mode & fs::write))
+	{
+		share |= FILE_SHARE_READ;
+	}
+
+	if (!test(mode, fs::lock + fs::unread) || !test(mode & fs::write))
 	{
 		share |= FILE_SHARE_WRITE | FILE_SHARE_DELETE;
 	}
@@ -944,10 +949,17 @@ fs::file::file(const std::string& path, bs_t<open_mode> mode)
 
 	if (test(mode & fs::append)) flags |= O_APPEND;
 	if (test(mode & fs::create)) flags |= O_CREAT;
-	if (test(mode & fs::trunc)) flags |= O_TRUNC;
+	if (test(mode & fs::trunc) && !test(mode, fs::lock + fs::unread)) flags |= O_TRUNC;
 	if (test(mode & fs::excl)) flags |= O_EXCL;
 
-	const int fd = ::open(path.c_str(), flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+	int perm = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
+
+	if (test(mode & fs::write) && test(mode & fs::unread))
+	{
+		perm = 0;
+	}
+
+	const int fd = ::open(path.c_str(), flags, perm);
 
 	if (fd == -1)
 	{
@@ -955,13 +967,19 @@ fs::file::file(const std::string& path, bs_t<open_mode> mode)
 		return;
 	}
 
-	if (test(mode & fs::unshare) && ::flock(fd, LOCK_EX | LOCK_NB) != 0)
+	if (test(mode & fs::write) && test(mode, fs::lock + fs::unread) && ::flock(fd, LOCK_EX | LOCK_NB) != 0)
 	{
 		g_tls_error = errno == EWOULDBLOCK ? fs::error::acces : to_error(errno);
 		::close(fd);
 		return;
 	}
 
+	if (test(mode & fs::trunc) && test(mode, fs::lock + fs::unread))
+	{
+		// Postpone truncation in order to avoid using O_TRUNC on a locked file
+		::ftruncate(fd, 0);
+	}
+
 	class unix_file final : public file_base, public get_native_handle
 	{
 		const int m_fd;
diff --git a/Utilities/File.h b/Utilities/File.h
index b2c35a0c53..ae679a1ee7 100644
--- a/Utilities/File.h
+++ b/Utilities/File.h
@@ -25,7 +25,8 @@ namespace fs
 		create,
 		trunc,
 		excl,
-		unshare,
+		lock,
+		unread,
 
 		__bitset_enum_max
 	};
@@ -36,7 +37,8 @@ namespace fs
 	constexpr auto create  = +open_mode::create; // Create file if it doesn't exist
 	constexpr auto trunc   = +open_mode::trunc; // Clear opened file if it's not empty
 	constexpr auto excl    = +open_mode::excl; // Failure if the file already exists (used with `create`)
-	constexpr auto unshare = +open_mode::unshare; // Prevent opening the file twice
+	constexpr auto lock    = +open_mode::lock; // Prevent opening the file more than once
+	constexpr auto unread  = +open_mode::unread; // Aggressively prevent reading the opened file (do not use)
 
 	constexpr auto rewrite = open_mode::write + open_mode::create + open_mode::trunc;
 
@@ -185,7 +187,7 @@ namespace fs
 		file() = default;
 
 		// Open file with specified mode
-		explicit file(const std::string& path, bs_t<open_mode> mode = ::fs::read);		
+		explicit file(const std::string& path, bs_t<open_mode> mode = ::fs::read);
 
 		// Open memory for read
 		explicit file(const void* ptr, std::size_t size);
@@ -400,7 +402,7 @@ namespace fs
 		{
 			m_dir = std::move(ptr);
 		}
-		
+
 		std::unique_ptr<dir_base> release()
 		{
 			return std::move(m_dir);
diff --git a/Utilities/Log.cpp b/Utilities/Log.cpp
index 8fc12391f8..97da466863 100644
--- a/Utilities/Log.cpp
+++ b/Utilities/Log.cpp
@@ -18,6 +18,7 @@ using namespace std::literals::chrono_literals;
 #include <Windows.h>
 #else
 #include <sys/mman.h>
+#include <sys/stat.h>
 #endif
 
 #include <zlib.h>
@@ -309,7 +310,7 @@ logs::file_writer::file_writer(const std::string& name)
 
 	try
 	{
-		if (!m_file.open(buf_name, fs::read + fs::write + fs::create + fs::trunc + fs::unshare))
+		if (!m_file.open(buf_name, fs::read + fs::rewrite + fs::lock))
 		{
 			if (fs::g_tls_error == fs::error::acces)
 			{
@@ -361,11 +362,18 @@ logs::file_writer::file_writer(const std::string& name)
 		// Actual log file (allowed to fail)
 		m_fout.open(log_name, fs::rewrite);
 
-		// Compressed log
-		if (!m_fout2.open(log_name + ".gz", fs::rewrite) || deflateInit2(&m_zs, 9, Z_DEFLATED, 16 + 15, 9, Z_DEFAULT_STRATEGY) != Z_OK)
+		// Compressed log, make it inaccessible (foolproof)
+		if (!m_fout2.open(log_name + ".gz", fs::rewrite + fs::unread) || deflateInit2(&m_zs, 9, Z_DEFLATED, 16 + 15, 9, Z_DEFAULT_STRATEGY) != Z_OK)
 		{
 			m_fout2.close();
 		}
+
+#ifdef _WIN32
+		// Autodelete compressed log file
+		FILE_DISPOSITION_INFO disp;
+		disp.DeleteFileW = TRUE;
+		SetFileInformationByHandle(m_fout2.get_handle(), FileDispositionInfo, &disp, sizeof(disp));
+#endif
 	}
 	catch (const std::exception& e)
 	{
@@ -443,9 +451,16 @@ logs::file_writer::~file_writer()
 	}
 
 #ifdef _WIN32
+	// Cancel compressed log file autodeletion
+	FILE_DISPOSITION_INFO disp;
+	disp.DeleteFileW = FALSE;
+	SetFileInformationByHandle(m_fout2.get_handle(), FileDispositionInfo, &disp, sizeof(disp));
+
 	UnmapViewOfFile(m_fptr);
 	CloseHandle(m_fmap);
 #else
+	// Restore compressed log file permissions
+	::fchmod(m_fout2.get_handle(), S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 	::munmap(m_fptr, s_log_size);
 #endif
 }
@@ -591,7 +606,7 @@ void logs::file_listener::log(u64 stamp, const logs::message& msg, const std::st
 	case level::_uninit: text = u8"·  "; break;
 	}
 
-	// Print miscosecond timestamp
+	// Print µs timestamp
 	const u64 hours = stamp / 3600'000'000;
 	const u64 mins = (stamp % 3600'000'000) / 60'000'000;
 	const u64 secs = (stamp % 60'000'000) / 1'000'000;