diff --git a/postfix/HISTORY b/postfix/HISTORY
index e9128c38d..16e094cb3 100644
--- a/postfix/HISTORY
+++ b/postfix/HISTORY
@@ -10583,6 +10583,11 @@ Apologies for any names omitted.
 	valid C. Bugs reported by Victor Duchovni. Files:
 	util/sys_defs.h, global/dsn_util.h, tls/tls_client.c.
 
+	Bugfix: when delivery to command failed, command output was
+	not reported. Fix was to enable format checks for the new
+	dsn_vstring_update() module. File: global/dsn_util.h,
+	global/pipe_command.c.
+
 Open problems:
 
 	Med: disable header address rewriting after XCLIENT?
diff --git a/postfix/src/global/dsn_util.h b/postfix/src/global/dsn_util.h
index eadb0975d..75c44aed5 100644
--- a/postfix/src/global/dsn_util.h
+++ b/postfix/src/global/dsn_util.h
@@ -72,7 +72,7 @@ typedef struct {
 } DSN_VSTRING;
 
 extern DSN_VSTRING *dsn_vstring_alloc(int);
-extern DSN_VSTRING *dsn_vstring_update(DSN_VSTRING *, const char *, const char *,...);
+extern PRINTFLIKE(3, 4) DSN_VSTRING *dsn_vstring_update(DSN_VSTRING *, const char *, const char *,...);
 extern void dsn_vstring_free(DSN_VSTRING *);
 
 /* LICENSE
diff --git a/postfix/src/global/mail_version.h b/postfix/src/global/mail_version.h
index 93f5e8bd5..1fb39eadc 100644
--- a/postfix/src/global/mail_version.h
+++ b/postfix/src/global/mail_version.h
@@ -20,7 +20,7 @@
   * Patches change the patchlevel and the release date. Snapshots change the
   * release date only.
   */
-#define MAIL_RELEASE_DATE	"20050331"
+#define MAIL_RELEASE_DATE	"20050401"
 #define MAIL_VERSION_NUMBER	"2.3"
 
 #define VAR_MAIL_VERSION	"mail_version"
diff --git a/postfix/src/global/pipe_command.c b/postfix/src/global/pipe_command.c
index 2653056c6..2e7461fea 100644
--- a/postfix/src/global/pipe_command.c
+++ b/postfix/src/global/pipe_command.c
@@ -582,7 +582,7 @@ int     pipe_command(VSTREAM *src, DSN_VSTRING *why,...)
 	    /* Use <sysexits.h> compatible exit status. */
 	    else if (SYS_EXITS_CODE(WEXITSTATUS(wait_status))) {
 		sp = sys_exits_detail(WEXITSTATUS(wait_status));
-		dsn_vstring_update(why, sp->dsn, "%s%s", sp->text,
+		dsn_vstring_update(why, sp->dsn, "%s%s%s", sp->text,
 			      log_len ? ". Command output: " : "", log_buf);
 		return (sp->dsn[0] == '4' ?
 			PIPE_STAT_DEFER : PIPE_STAT_BOUNCE);