diff --git a/docs/man/maddy-imap.5.scd b/docs/man/maddy-imap.5.scd
index 49dbf39..782257b 100644
--- a/docs/man/maddy-imap.5.scd
+++ b/docs/man/maddy-imap.5.scd
@@ -96,8 +96,8 @@ command executable_name args... { }
 
 Same as check.command, following placeholders are supported for command
 arguments: {source_ip}, {source_host}, {source_rdns}, {msg_id}, {auth_user},
-{sender}, {rcpt_to}, {original_rcpt_to}, {address}. Note: placeholders in command
-name are not processed to avoid possible command injection attacks.
+{sender}, {rcpt_to}, {original_rcpt_to}, {address}, {subject}. Note: placeholders
+in command name are not processed to avoid possible command injection attacks.
 
 Additionally, for imap.filter.command, {account_name} placeholder is replaced
 with effective IMAP account name.
diff --git a/internal/imap_filter/command/command.go b/internal/imap_filter/command/command.go
index 51495a1..58146dc 100644
--- a/internal/imap_filter/command/command.go
+++ b/internal/imap_filter/command/command.go
@@ -49,7 +49,7 @@ type Check struct {
 }
 
 func (c *Check) IMAPFilter(accountName string, rcptTo string, msgMeta *module.MsgMetadata, hdr textproto.Header, body buffer.Buffer) (folder string, flags []string, err error) {
-	cmd, args := c.expandCommand(msgMeta, accountName, rcptTo)
+	cmd, args := c.expandCommand(msgMeta, accountName, rcptTo, hdr)
 
 	var buf bytes.Buffer
 	_ = textproto.WriteHeader(&buf, hdr)
@@ -95,7 +95,7 @@ func (c *Check) Init(cfg *config.Map) error {
 	return err
 }
 
-func (c *Check) expandCommand(msgMeta *module.MsgMetadata, accountName string, rcptTo string) (string, []string) {
+func (c *Check) expandCommand(msgMeta *module.MsgMetadata, accountName string, rcptTo string, hdr textproto.Header) (string, []string) {
 	expArgs := make([]string, len(c.cmdArgs))
 
 	for i, arg := range c.cmdArgs {
@@ -144,6 +144,8 @@ func (c *Check) expandCommand(msgMeta *module.MsgMetadata, accountName string, r
 					oldestOriginalRcpt = originalRcpt
 				}
 				return oldestOriginalRcpt
+			case "{subject}":
+				return hdr.Get("Subject")
 			case "{account_name}":
 				return accountName
 			}