diff --git a/main.cc b/main.cc
index 9397965..d2e623e 100644
--- a/main.cc
+++ b/main.cc
@@ -202,13 +202,14 @@ bool check_files( const char * const iname, const char * const oname,
     }
   if( check_identical( iname, oname ) )
     { show_error( "Infile and outfile are the same." ); return false; }
-  if( !force || preallocate )
+  bool nulldev = !std::strcmp( oname, "/dev/null" );
+  if( !(force || nulldev) || preallocate )
     {
     struct stat st;
     if( stat( oname, &st ) == 0 && !S_ISREG( st.st_mode ) )
       {
       show_error( "Output file exists and is not a regular file." );
-      if( !force )
+      if( !(force || nulldev) )
         {
         show_error( "Use `--force' if you really want to overwrite it, but be" );
         show_error( "aware that all existing data in output file will be lost.", 0, true );