diff --git a/src/lib-sieve/plugins/body/tst-body.c b/src/lib-sieve/plugins/body/tst-body.c
index 8ef5660878ed78df6f738b7291ee0cfa02415fb3..3a9e058c6a07cf9fe099d3e4835e58bec310c53e 100644
--- a/src/lib-sieve/plugins/body/tst-body.c
+++ b/src/lib-sieve/plugins/body/tst-body.c
@@ -154,13 +154,10 @@ static bool tag_body_transform_validate
 		 *   :content <content-types: string-list>
 		 */
 		if ( !sieve_validate_tag_parameter
-			(valdtr, cmd, tag, *arg, SAAT_STRING_LIST) ) {
+			(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING_LIST, FALSE) ) {
 			return FALSE;
 		}
 		
-		if ( !sieve_validator_argument_activate(valdtr, cmd, *arg, FALSE) )
-			return FALSE;
-		
 		/* Assign tag parameters */
 		tag->parameters = *arg;
 		*arg = sieve_ast_arguments_detach(*arg,1);
diff --git a/src/lib-sieve/plugins/date/tst-date.c b/src/lib-sieve/plugins/date/tst-date.c
index c2bbd65ccc8444c0bb10b6d407df1ffbc564c153..30d51903488f318e88297317ae0968b44cbda786 100644
--- a/src/lib-sieve/plugins/date/tst-date.c
+++ b/src/lib-sieve/plugins/date/tst-date.c
@@ -173,7 +173,7 @@ static bool tag_zone_validate
 		 *   :zone <time-zone: string>
 		 */
 		if ( !sieve_validate_tag_parameter
-			(valdtr, cmd, tag, *arg, SAAT_STRING) ) {
+			(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING, FALSE) ) {
 			return FALSE;
 		}
 
diff --git a/src/lib-sieve/plugins/enotify/cmd-notify.c b/src/lib-sieve/plugins/enotify/cmd-notify.c
index e0f9afcaa06401e65461c67a91904b77d2054438..5b325f822ee0ee5955aa0a092ffa137546866f95 100644
--- a/src/lib-sieve/plugins/enotify/cmd-notify.c
+++ b/src/lib-sieve/plugins/enotify/cmd-notify.c
@@ -180,7 +180,8 @@ static bool cmd_notify_validate_string_tag
 	 *   :from <string>
 	 *   :message <string>
 	 */
-	if ( !sieve_validate_tag_parameter(valdtr, cmd, tag, *arg, SAAT_STRING) )
+	if ( !sieve_validate_tag_parameter
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING, FALSE) )
 		return FALSE;
 
 	if ( sieve_argument_is(tag, notify_from_tag) ) {
@@ -213,7 +214,8 @@ static bool cmd_notify_validate_stringlist_tag
 	/* Check syntax:
 	 *   :options string-list
 	 */
-	if ( !sieve_validate_tag_parameter(valdtr, cmd, tag, *arg, SAAT_STRING_LIST) ) 
+	if ( !sieve_validate_tag_parameter
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING_LIST, FALSE) ) 
 		return FALSE;
 		
 	/* Assign context */
diff --git a/src/lib-sieve/plugins/imap4flags/tag-flags.c b/src/lib-sieve/plugins/imap4flags/tag-flags.c
index 837baaa458739bfdee41857dd3fb5421465719d4..026faf0b6e7bc9de7952f572fd2d3775f6d481da 100644
--- a/src/lib-sieve/plugins/imap4flags/tag-flags.c
+++ b/src/lib-sieve/plugins/imap4flags/tag-flags.c
@@ -128,7 +128,7 @@ static bool tag_flags_validate
 	 *   :flags <list-of-flags: string-list>
 	 */
 	if ( !sieve_validate_tag_parameter
-		(valdtr, cmd, tag, *arg, SAAT_STRING_LIST) ) {
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING_LIST, FALSE) ) {
 		return FALSE;
 	}
 	
diff --git a/src/lib-sieve/plugins/notify/cmd-notify.c b/src/lib-sieve/plugins/notify/cmd-notify.c
index 5592cce3caf94bed11489361cbfcb57cc38323d6..d7d31742f74c676fbb1476bd2e84c4fafeaba112 100644
--- a/src/lib-sieve/plugins/notify/cmd-notify.c
+++ b/src/lib-sieve/plugins/notify/cmd-notify.c
@@ -192,7 +192,8 @@ static bool cmd_notify_validate_string_tag
 	 *   :method <string>
 	 *   :message <string>
 	 */
-	if ( !sieve_validate_tag_parameter(valdtr, cmd, tag, *arg, SAAT_STRING) )
+	if ( !sieve_validate_tag_parameter
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING, FALSE) )
 		return FALSE;
 
 	if ( sieve_argument_is(tag, notify_method_tag) ) {
@@ -231,7 +232,8 @@ static bool cmd_notify_validate_stringlist_tag
 	/* Check syntax:
 	 *   :options string-list
 	 */
-	if ( !sieve_validate_tag_parameter(valdtr, cmd, tag, *arg, SAAT_STRING_LIST) ) 
+	if ( !sieve_validate_tag_parameter
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING_LIST, FALSE) ) 
 		return FALSE;
 		
 	/* Assign context */
diff --git a/src/lib-sieve/plugins/vacation/cmd-vacation.c b/src/lib-sieve/plugins/vacation/cmd-vacation.c
index b56188446d1464a1b4ddf8f2c5b0a53be1fbcd08..255f4173dc2b939eaffab680634dd4c4f13e4f6d 100644
--- a/src/lib-sieve/plugins/vacation/cmd-vacation.c
+++ b/src/lib-sieve/plugins/vacation/cmd-vacation.c
@@ -242,7 +242,7 @@ static bool cmd_vacation_validate_number_tag
 	 *   :days number
 	 */
 	if ( !sieve_validate_tag_parameter
-		(valdtr, cmd, tag, *arg, SAAT_NUMBER) ) {
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_NUMBER, FALSE) ) {
 		return FALSE;
 	}
 
@@ -274,7 +274,7 @@ static bool cmd_vacation_validate_string_tag
 	 *   :handle string
 	 */
 	if ( !sieve_validate_tag_parameter
-		(valdtr, cmd, tag, *arg, SAAT_STRING) ) {
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING, FALSE) ) {
 		return FALSE;
 	}
 
@@ -332,7 +332,7 @@ static bool cmd_vacation_validate_stringlist_tag
 	 *   :addresses string-list
 	 */
 	if ( !sieve_validate_tag_parameter
-		(valdtr, cmd, tag, *arg, SAAT_STRING_LIST) ) {
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING_LIST, FALSE) ) {
 		return FALSE;
 	}
 	
diff --git a/src/lib-sieve/sieve-validator.c b/src/lib-sieve/sieve-validator.c
index e385ec1186bf0b0136f3c5f89354b183929820a3..642e34e1b0aaa8cfe57a22c9e0037ef6410ed36c 100644
--- a/src/lib-sieve/sieve-validator.c
+++ b/src/lib-sieve/sieve-validator.c
@@ -803,14 +803,18 @@ bool sieve_validate_positional_argument
 bool sieve_validate_tag_parameter
 (struct sieve_validator *valdtr, struct sieve_command *cmd,
 	struct sieve_ast_argument *tag, struct sieve_ast_argument *param,
-	enum sieve_ast_argument_type req_type)
+	const char *arg_name, unsigned int arg_pos,
+	enum sieve_ast_argument_type req_type, bool constant)
 {
 	if ( param == NULL ) {
+		const char *position = ( arg_pos == 0 ? "" :
+			t_strdup_printf(" %d (%s)", arg_pos, arg_name) );
+ 
 		sieve_argument_validate_error(valdtr, tag, 
-			"the :%s tag for the %s %s requires %s as parameter, "
-			"but no more arguments were found", sieve_ast_argument_tag(tag), 
+			"the :%s tag for the %s %s requires %s as parameter %s, "
+			"but no parameters were found", sieve_ast_argument_tag(tag), 
 			sieve_command_identifier(cmd), sieve_command_type_name(cmd),
-			sieve_ast_argument_type_name(req_type));
+			sieve_ast_argument_type_name(req_type), position);
 		return FALSE;	
 	}
 
@@ -818,15 +822,19 @@ bool sieve_validate_tag_parameter
 		(sieve_ast_argument_type(param) != SAAT_STRING || 
 			req_type != SAAT_STRING_LIST) ) 
 	{
+		const char *position = ( arg_pos == 0 ? "" :
+			t_strdup_printf(" %d (%s)", arg_pos, arg_name) );
+
 		sieve_argument_validate_error(valdtr, param, 
-			"the :%s tag for the %s %s requires %s as parameter, "
+			"the :%s tag for the %s %s requires %s as parameter%s, "
 			"but %s was found", sieve_ast_argument_tag(tag), 
 			sieve_command_identifier(cmd), sieve_command_type_name(cmd),
-			sieve_ast_argument_type_name(req_type),	sieve_ast_argument_name(param));
+			sieve_ast_argument_type_name(req_type),	position,
+			sieve_ast_argument_name(param));
 		return FALSE;
 	}
 
-	if ( !sieve_validator_argument_activate(valdtr, cmd, param, FALSE) )
+	if ( !sieve_validator_argument_activate(valdtr, cmd, param, constant) )
 		return FALSE;
 
 	param->argument->id_code = tag->argument->id_code;
diff --git a/src/lib-sieve/sieve-validator.h b/src/lib-sieve/sieve-validator.h
index 5e34b25257fe4ef49a5682659fe3fca6b8589c3f..a1cf1fc8a718c4dd059806557bba75c21717d21d 100644
--- a/src/lib-sieve/sieve-validator.h
+++ b/src/lib-sieve/sieve-validator.h
@@ -114,7 +114,8 @@ bool sieve_validator_argument_activate
 bool sieve_validate_tag_parameter
 	(struct sieve_validator *valdtr, struct sieve_command *cmd,
 		struct sieve_ast_argument *tag, struct sieve_ast_argument *param,
-		enum sieve_ast_argument_type req_type);
+		const char *arg_name, unsigned int arg_pos,
+		enum sieve_ast_argument_type req_type, bool constant);
 	
 /* 
  * Extension support
diff --git a/src/testsuite/cmd-test-message.c b/src/testsuite/cmd-test-message.c
index 2cd19a8999c2d18ae60fbaea22ef078ea6eeec27..c1dbbcc86b3c13a6b28c868356d17d682a18e7bd 100644
--- a/src/testsuite/cmd-test-message.c
+++ b/src/testsuite/cmd-test-message.c
@@ -193,7 +193,7 @@ static bool cmd_test_message_validate_folder_tag
 	 *   :folder string
 	 */
 	if ( !sieve_validate_tag_parameter
-		(valdtr, cmd, tag, *arg, SAAT_STRING) ) {
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_STRING, FALSE) ) {
 		return FALSE;
 	}
 
diff --git a/src/testsuite/tst-test-error.c b/src/testsuite/tst-test-error.c
index c393b622b7139d67c783e47f79e619545ecbd3e1..f5ae3b3c756c3ecb203e5079c1b0df7f185f9cb6 100644
--- a/src/testsuite/tst-test-error.c
+++ b/src/testsuite/tst-test-error.c
@@ -102,7 +102,7 @@ static bool tst_test_error_validate_index_tag
 	 *   :index number
 	 */
 	if ( !sieve_validate_tag_parameter
-		(valdtr, cmd, tag, *arg, SAAT_NUMBER) ) {
+		(valdtr, cmd, tag, *arg, NULL, 0, SAAT_NUMBER, FALSE) ) {
 		return FALSE;
 	}
 
diff --git a/src/testsuite/tst-test-result.c b/src/testsuite/tst-test-result.c
index 0d4eededc680c6c3ab50f894a04d49d56b8725d0..d09e87df1738b70bd86065ba614589f5455a7836 100644
--- a/src/testsuite/tst-test-result.c
+++ b/src/testsuite/tst-test-result.c
@@ -107,7 +107,7 @@ static bool tst_test_result_validate_index_tag
 	 *   :index number
 	 */
 	if ( !sieve_validate_tag_parameter
-		(validator, cmd, tag, *arg, SAAT_NUMBER) ) {
+		(validator, cmd, tag, *arg, NULL, 0, SAAT_NUMBER, FALSE) ) {
 		return FALSE;
 	}