diff --git a/aegisub/libaegisub/windows/util_win.cpp b/aegisub/libaegisub/windows/util_win.cpp
index 53b833aae..158a45dca 100644
--- a/aegisub/libaegisub/windows/util_win.cpp
+++ b/aegisub/libaegisub/windows/util_win.cpp
@@ -57,7 +57,8 @@ void Rename(const std::string& from, const std::string& to) {
 		acs::CheckDirWrite(DirName(to));
 	}
 
-	MoveFileEx(ConvertW(from).c_str(), ConvertW(to).c_str(), MOVEFILE_REPLACE_EXISTING);
+	if (!MoveFileEx(ConvertW(from).c_str(), ConvertW(to).c_str(), MOVEFILE_REPLACE_EXISTING))
+		throw agi::FileNotAccessibleError("Can not overwrite file: " + ErrorString(GetLastError()));
 }
 
 std::string ErrorString(DWORD error) {