diff --git a/common.sh b/common.sh
index 75a0535..efc6ab5 100644
--- a/common.sh
+++ b/common.sh
@@ -13,6 +13,10 @@ error() {
 	printf "$@" 1>&2
 	echo '' 1>&2
 }
+
+# $1 - value
+# $2 - param name
+# (optional) $3 - anything, trigger check for non-negative
 _check_argument_is_number() {
 	if [[ "$1" == [0-9]* ]]; then
 		return 0
@@ -24,6 +28,9 @@ _check_argument_is_number() {
 		return 1
 	fi
 }
+
+# $1 - value
+# $2 - param name
 _check_argument_value() {
 	if [[ "$1" < "$2" ]]; then
 		error $"Argument to %s must be greater than %s" "$2" "$3"
@@ -32,6 +39,9 @@ _check_argument_value() {
 		return 0
 	fi
 }
+
+# $1 - value
+# $2 - param name
 _check_argument_is_string() {
 	if [[ "$1" == *[[:blank:]]* ]]; then
 		error $"Argument to %s must be a string without spaces"  "$2"
@@ -41,3 +51,27 @@ _check_argument_is_string() {
 	fi
 }
 
+# $1 - value
+# $2 - param name
+_check_argument_is_boolean(){
+	case "$1" in
+		"yes" ) return 0 ;;
+		"no" ) return 0 ;;
+		"" )
+			error $"Value of %s is empty, set yes or no" "$2"
+		;;
+		* )
+			error $"String %s is not a boolean, set yes or no" "$1"
+		;;
+	esac
+}
+
+# $1 - value
+# $2 - param name
+_check_argument_is_non_negative_number(){
+	# 2>/dev/null to avoid odd output if $1 is not a number
+	if ! test "$1" -lt 0 2>/dev/null; then
+		error $"Value of %s must be a non-negative number" "$2"
+		return 1
+	fi
+}
diff --git a/mikhailnov.sh b/mikhailnov.sh
index d08abbb..6d251b6 100755
--- a/mikhailnov.sh
+++ b/mikhailnov.sh
@@ -7,31 +7,6 @@ _is_auditd_enabled(){
 	systemctl is-active -q autitd
 }
 
-# $1 - value
-# $2 - param name
-_auditd_conf_is_boolean(){
-	case "$1" in
-		"yes" ) return 0 ;;
-		"no" ) return 0 ;;
-		"" )
-			error $"Value of %s is empty, set yes or no" "$2"
-		;;
-		* )
-			error $"String %s is not a boolean, set yes or no" "$1"
-		;;
-	esac
-}
-
-# $1 - value
-# $2 - param name
-_auditd_conf_is_non_negative_number(){
-	# 2>/dev/null to avoid odd output if $1 is not a number
-	if ! test "$1" -lt 0 2>/dev/null; then
-		error $"Value of %s must be a non-negative number" "$2"
-		return 1
-	fi
-}
-
 _mk_auditd_config(){
 	local failed=0
 	local local_events="yes"
@@ -56,7 +31,7 @@ _mk_auditd_config(){
 	do
 		case "$1" in
 			"--local_events" )
-				_auditd_conf_is_boolean "$1" "local_events" || failed=1
+				_check_argument_is_boolean "$1" "local_events" || failed=1
 				local_events="$1"
 				shift
 			;;
@@ -78,7 +53,7 @@ _mk_auditd_config(){
 				fi
 			;;
 			"--write_logs" )
-				_auditd_conf_is_boolean "$1" "write_logs"  || failed=1
+				_check_argument_is_boolean "$1" "write_logs"  || failed=1
 				write_logs="$1"
 				shift
 			;;
@@ -100,7 +75,7 @@ _mk_auditd_config(){
 				shift
 			;;
 			"--priority_boost" )
-				_auditd_conf_is_non_negative_number "$1" "priority_boost" || failed=1
+				_check_argument_is_non_negative_number "$1" "priority_boost" || failed=1
 				priority_boost="$1"
 				shift
 			;;
@@ -122,7 +97,7 @@ _mk_auditd_config(){
 			;;
 			"--freq" )
 				if [ "$flush" = "incremental_async" ]; then
-					_auditd_conf_is_non_negative_number "$1" "freq" || failed=1
+					_check_argument_is_non_negative_number "$1" "freq" || failed=1
 					freq="$1"
 					shift
 				else
@@ -156,7 +131,7 @@ _mk_auditd_config(){
 					error $"Parameter %s makes sense only when %s" "num_logs" "max_log_file_action=rotate"
 					failed=1
 				else
-					_auditd_conf_is_non_negative_number "$1" "num_logs" || failed=1
+					_check_argument_is_non_negative_number "$1" "num_logs" || failed=1
 					num_logs="$1"
 					shift
 				fi
diff --git a/test_back_pwquality.sh b/test_back_pwquality.sh
index 995cb7a..95cdc11 100644
--- a/test_back_pwquality.sh
+++ b/test_back_pwquality.sh
@@ -21,6 +21,9 @@ _main(){
 	_mk_pwquality_conf --minclass STRING 1>/dev/null && { echo failed test 1; failed="$((++failed))"; }
 	_mk_pwquality_conf --usercheck 1 1>/dev/null || { echo failed test 2 && failed="$((++failed))" ;}
 	! _mk_pwquality_conf --enforcing 1 --retry --usersubstr 1>/dev/null || { echo failed test 3 && failed="$((++failed))" ;}
+	_mk_pwquality_conf --ucredit -3 || { echo failed test 3 && failed="$((++failed))" ;}
+	_mk_pwquality_conf --ucredit 3 || { echo failed test 3 && failed="$((++failed))" ;}
+	_mk_pwquality_conf --ucredit +3 || { echo failed test 3 && failed="$((++failed))" ;}
 }
 
 _main