diff --git a/src/commands.cc b/src/commands.cc
index 4a5eceaf..6143179d 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -323,7 +323,7 @@ void write_buffer(const ParametersParser& parser, Context& context, const ShellC
         throw runtime_error("cannot overwrite the buffer when in readonly mode");
 
     auto filename = parser.positional_count() == 0 ?
-                        buffer.name() : parse_filename(parser[0]);
+                    buffer.name() : parse_filename(parser[0]);
 
     context.hooks().run_hook("BufWritePre", filename, context);
     write_buffer_to_file(buffer, filename);
diff --git a/src/file.cc b/src/file.cc
index 29e285e9..bf592689 100644
--- a/src/file.cc
+++ b/src/file.cc
@@ -280,8 +280,7 @@ void write_buffer_to_fd(Buffer& buffer, int fd)
 
 void write_buffer_to_file(Buffer& buffer, StringView filename)
 {
-    int fd = open(parse_filename(filename).c_str(),
-                  O_CREAT | O_WRONLY | O_TRUNC, 0644);
+    int fd = open(filename.zstr(), O_CREAT | O_WRONLY | O_TRUNC, 0644);
     if (fd == -1)
         throw file_access_error(filename, strerror(errno));
 
diff --git a/src/main.cc b/src/main.cc
index 24f1ae4b..845a8ab5 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -692,9 +692,9 @@ int run_filter(StringView keystr, StringView commands, ConstArrayView<StringView
         {
             Buffer* buffer = open_file_buffer(file);
             if (not suffix_backup.empty())
-                write_buffer_to_file(*buffer, file + suffix_backup);
+                write_buffer_to_file(*buffer, buffer->name() + suffix_backup);
             apply_to_buffer(*buffer);
-            write_buffer_to_file(*buffer, file);
+            write_buffer_to_file(*buffer, buffer->name());
             buffer_manager.delete_buffer(*buffer);
         }
         if (not isatty(0))