diff --git a/miniserv.pl b/miniserv.pl
index 21b32b84d..8cd462de8 100755
--- a/miniserv.pl
+++ b/miniserv.pl
@@ -139,22 +139,15 @@ if (-l $perl_path) {
 # Check vital config options
 &update_vital_config();
 
-# Check if already running via the PID file
-if (open(PIDFILE, $config{'pidfile'})) {
+# Check if already running via the PID file. In foreground mode, systemd or
+# the socket bind owns duplicate-start detection.
+if (!$config{'nofork'} && !$nofork_argv && open(PIDFILE, $config{'pidfile'})) {
 	my $already = <PIDFILE>;
 	close(PIDFILE);
 	chomp($already);
 	$already =~ s/^\s+|\s+$//g;
 	if ($already =~ /^\d+$/ && $already != $$ && kill(0, $already)) {
-		my $active = &pid_is_miniserv_for_config($already, $config_file);
-		if (defined($active) && !$active) {
-			warn "Ignoring stale Webmin PID file $config{'pidfile'} ".
-			     "for unrelated PID $already\n";
-			unlink($config{'pidfile'});
-			}
-		else {
-			die "Webmin is already running with PID $already\n";
-			}
+		die "Webmin is already running with PID $already\n";
 		}
 	}
 
@@ -5191,56 +5184,6 @@ close($fh);
 return $rv;
 }
 
-# read_process_cmdline(pid)
-# Returns a process command line from /proc, or undef if unavailable.
-sub read_process_cmdline
-{
-my ($pid) = @_;
-return undef if (!$pid || $pid !~ /^\d+$/);
-return &read_any_file("/proc/$pid/cmdline");
-}
-
-# same_config_file(file1, file2)
-# Returns 1 if two config paths refer to the same file.
-sub same_config_file
-{
-my ($file1, $file2) = @_;
-return 0 if (!$file1 || !$file2);
-return 1 if ($file1 eq $file2);
-my @stat1 = stat($file1);
-my @stat2 = stat($file2);
-return @stat1 && @stat2 && $stat1[0] == $stat2[0] &&
-       $stat1[1] == $stat2[1];
-}
-
-# pid_is_miniserv_for_config(pid, config-file)
-# Returns 1 if pid appears to be miniserv for this config, 0 if it is a
-# different process, or undef if this platform cannot tell.
-sub pid_is_miniserv_for_config
-{
-my ($pid, $config_file) = @_;
-my $cmdline = &read_process_cmdline($pid);
-return undef if (!defined($cmdline));
-return 0 if ($cmdline eq "");
-my @args = split(/\0/, $cmdline);
-my $script_idx;
-for(my $i=0; $i<@args; $i++) {
-	if ($args[$i] =~ /(?:^|\/)miniserv\.pl$/) {
-		$script_idx = $i;
-		last;
-		}
-	}
-return 0 if (!defined($script_idx));
-my $config_arg;
-for(my $i=$script_idx+1; $i<@args; $i++) {
-	next if ($args[$i] =~ /^-/);
-	$config_arg = $args[$i];
-	last;
-	}
-return defined($config_arg) ?
-       (&same_config_file($config_arg, $config_file) ? 1 : 0) : undef;
-}
-
 # update_vital_config()
 # Updates %config with defaults, and dies if something vital is missing
 sub update_vital_config
diff --git a/t/miniserv.t b/t/miniserv.t
index 05c4fcd97..59a690352 100644
--- a/t/miniserv.t
+++ b/t/miniserv.t
@@ -1282,70 +1282,6 @@ subtest 'read_any_file' => sub {
 	   'open failure returns undef');
 };
 
-# pid_is_miniserv_for_config — avoids stale pidfiles with reused PIDs
-subtest 'pid_is_miniserv_for_config' => sub {
-	my $config = '/etc/webmin/miniserv.conf';
-	my $pid = $$;
-
-	{
-		no warnings 'redefine';
-		local *miniserv::read_process_cmdline = sub {
-			return join("\0", '/usr/sbin/dovecot', '-F');
-			};
-		is(miniserv::pid_is_miniserv_for_config($pid, $config), 0,
-		   'live unrelated PID is not treated as active miniserv');
-	}
-
-	{
-		no warnings 'redefine';
-		local *miniserv::read_process_cmdline = sub {
-			return join("\0", '/usr/bin/perl',
-				    '/usr/libexec/webmin/miniserv.pl',
-				    '--nofork', $config);
-			};
-		is(miniserv::pid_is_miniserv_for_config($pid, $config), 1,
-		   'matching miniserv config is treated as active');
-	}
-
-	{
-		require File::Temp;
-		my ($fh, $real_config) = File::Temp::tempfile(UNLINK => 1);
-		close($fh);
-		my $link_config = "$real_config.link";
-		SKIP: {
-			symlink($real_config, $link_config) ||
-				skip 'symlinks are unavailable', 1;
-			no warnings 'redefine';
-			local *miniserv::read_process_cmdline = sub {
-				return join("\0", '/usr/bin/perl',
-					    '/usr/libexec/webmin/miniserv.pl',
-					    $link_config);
-				};
-			is(miniserv::pid_is_miniserv_for_config($pid, $real_config), 1,
-			   'symlinked config path is matched by inode');
-			unlink($link_config);
-			}
-	}
-
-	{
-		no warnings 'redefine';
-		local *miniserv::read_process_cmdline = sub {
-			return join("\0", '/usr/bin/perl',
-				    '/usr/libexec/usermin/miniserv.pl',
-				    '--nofork', '/etc/usermin/miniserv.conf');
-			};
-		is(miniserv::pid_is_miniserv_for_config($pid, $config), 0,
-		   'different miniserv config is not treated as active');
-	}
-
-	{
-		no warnings 'redefine';
-		local *miniserv::read_process_cmdline = sub { return undef; };
-		is(miniserv::pid_is_miniserv_for_config($pid, $config), undef,
-		   'unreadable process command line keeps conservative behavior');
-	}
-};
-
 # read_mime_types — populates %mime from file + addtype_* config
 subtest 'read_mime_types' => sub {
 	no warnings 'once';