diff --git a/include/fast_io_hosted/platforms/win32.h b/include/fast_io_hosted/platforms/win32.h
index 2b3baae9e..7f12f93a4 100644
--- a/include/fast_io_hosted/platforms/win32.h
+++ b/include/fast_io_hosted/platforms/win32.h
@@ -261,11 +261,11 @@ inline constexpr win32_open_mode calculate_win32_open_mode(open_mode_perms ompm)
 	}
 	if ((value & open_mode::no_shared_write) == open_mode::none)
 	{
-		mode.dwShareMode |= 2; // FILE_SHARE_DELETE
+		mode.dwShareMode |= 2; // FILE_SHARE_WRITE
 	}
 	if ((value & open_mode::shared_delete) != open_mode::none)
 	{
-		mode.dwShareMode |= 4; // FILE_SHARE_WRITE
+		mode.dwShareMode |= 4; // FILE_SHARE_DELETE
 	}
 	if ((value & open_mode::app) != open_mode::none)
 	{
@@ -357,7 +357,7 @@ inline constexpr win32_open_mode calculate_win32_open_mode(open_mode_perms ompm)
 			mode.dwCreationDisposition = 2; // CREATE_ALWAYS
 		}
 	}
-	else if ((value & open_mode::in) == open_mode::none)
+	else if ((value & open_mode::in) != open_mode::none)
 	{
 		if ((value & open_mode::app) != open_mode::none)
 		{
@@ -379,6 +379,10 @@ inline constexpr win32_open_mode calculate_win32_open_mode(open_mode_perms ompm)
 	{
 		mode.dwCreationDisposition = 4; // OPEN_ALWAYS
 	}
+	else if ((value & open_mode::out) != open_mode::none)
+	{
+		mode.dwCreationDisposition = 2; // CREATE_ALWAYS
+	}
 	else
 	{
 		mode.dwCreationDisposition = 3; // OPEN_EXISTING