diff --git a/administrator/components/com_users/config.xml b/administrator/components/com_users/config.xml
index 56959fee4c39e..39bb03f683e85 100644
--- a/administrator/components/com_users/config.xml
+++ b/administrator/components/com_users/config.xml
@@ -205,6 +205,17 @@
 			default="0"
 		/>
 
+		<field
+			name="minimum_lowercase"
+			type="integer"
+			label="COM_USERS_CONFIG_FIELD_MINIMUM_LOWERCASE"
+			description="COM_USERS_CONFIG_FIELD_MINIMUM_LOWERCASE_DESC"
+			first="0"
+			last="98"
+			step="1"
+			default="0"
+		/>
+
 	</fieldset>
 
 	<fieldset
diff --git a/administrator/language/en-GB/en-GB.com_admin.ini b/administrator/language/en-GB/en-GB.com_admin.ini
index ad37fcaa1179d..d54265d16b10d 100644
--- a/administrator/language/en-GB/en-GB.com_admin.ini
+++ b/administrator/language/en-GB/en-GB.com_admin.ini
@@ -193,10 +193,12 @@ COM_ADMIN_ZLIB_ENABLED="Zlib Enabled"
 ; Messages
 COM_USERS_MSG_NOT_ENOUGH_INTEGERS_N="Password does not have enough digits. At least %s digits are required."
 COM_USERS_MSG_NOT_ENOUGH_INTEGERS_N_1="Password does not have enough digits. At least 1 digit is required."
+COM_USERS_MSG_NOT_ENOUGH_LOWERCASE_LETTERS_N="Password does not have enough lower case characters. At least %s lower case characters are required."
+COM_USERS_MSG_NOT_ENOUGH_LOWERCASE_LETTERS_N_1="Password does not have enough lower case characters. At least 1 lower case character is required."
 COM_USERS_MSG_NOT_ENOUGH_SYMBOLS_N="Password does not have enough symbols. At least %s symbols are required."
 COM_USERS_MSG_NOT_ENOUGH_SYMBOLS_N_1="Password does not have enough symbols. At least 1 symbol is required."
-COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N="Password does not have enough uppercase characters. At least %s upper case characters are required."
-COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N_1="Password does not have enough uppercase characters. At least 1 upper case character is required."
+COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N="Password does not have enough upper case characters. At least %s upper case characters are required."
+COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N_1="Password does not have enough upper case characters. At least 1 upper case character is required."
 COM_USERS_MSG_PASSWORD_TOO_LONG="Password is too long. Passwords must be less than 100 characters."
 COM_USERS_MSG_PASSWORD_TOO_SHORT_N="Password is too short. Passwords must have at least %s characters."
 COM_USERS_MSG_SPACES_IN_PASSWORD="Password must not have spaces at the beginning or end."
diff --git a/administrator/language/en-GB/en-GB.com_users.ini b/administrator/language/en-GB/en-GB.com_users.ini
index 3fb61fc4a20a9..d89be9d7e4c8d 100644
--- a/administrator/language/en-GB/en-GB.com_users.ini
+++ b/administrator/language/en-GB/en-GB.com_users.ini
@@ -46,6 +46,8 @@ COM_USERS_CONFIG_FIELD_MAILTOADMIN_DESC="If set to Yes then a notification mail
 COM_USERS_CONFIG_FIELD_MAILTOADMIN_LABEL="Send Mail to Administrators"
 COM_USERS_CONFIG_FIELD_MINIMUM_INTEGERS="Minimum Integers"
 COM_USERS_CONFIG_FIELD_MINIMUM_INTEGERS_DESC="Set the minimum number of integers that must be included in a password."
+COM_USERS_CONFIG_FIELD_MINIMUM_LOWERCASE="Minimum Lower Case"
+COM_USERS_CONFIG_FIELD_MINIMUM_LOWERCASE_DESC="Set the minimum number of lower case alphabetical characters required for a password."
 COM_USERS_CONFIG_FIELD_MINIMUM_PASSWORD_LENGTH="Minimum Length"
 COM_USERS_CONFIG_FIELD_MINIMUM_PASSWORD_LENGTH_DESC="Set the minimum length for a password."
 COM_USERS_CONFIG_FIELD_MINIMUM_SYMBOLS="Minimum Symbols"
@@ -228,10 +230,12 @@ COM_USERS_MASS_MAIL="Mass Mail Users"
 COM_USERS_MASS_MAIL_DESC="Mass Mail options."
 COM_USERS_MSG_NOT_ENOUGH_INTEGERS_N="Password does not have enough digits. At least %s digits are required."
 COM_USERS_MSG_NOT_ENOUGH_INTEGERS_N_1="Password does not have enough digits. At least 1 digit is required."
+COM_USERS_MSG_NOT_ENOUGH_LOWERCASE_LETTERS_N="Password does not have enough lower case characters. At least %s lower case characters are required."
+COM_USERS_MSG_NOT_ENOUGH_LOWERCASE_LETTERS_N_1="Password does not have enough lower case characters. At least 1 lower case character is required."
 COM_USERS_MSG_NOT_ENOUGH_SYMBOLS_N="Password does not have enough symbols. At least %s symbols are required."
 COM_USERS_MSG_NOT_ENOUGH_SYMBOLS_N_1="Password does not have enough symbols. At least 1 symbol is required."
-COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N="Password does not have enough uppercase characters. At least %s upper case characters are required."
-COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N_1="Password does not have enough uppercase characters. At least 1 upper case character is required."
+COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N="Password does not have enough upper case characters. At least %s upper case characters are required."
+COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N_1="Password does not have enough upper case characters. At least 1 upper case character is required."
 COM_USERS_MSG_PASSWORD_TOO_LONG="Password is too long. Passwords must be less than 100 characters."
 COM_USERS_MSG_PASSWORD_TOO_SHORT_N="Password is too short. Passwords must have at least %s characters."
 COM_USERS_MSG_SPACES_IN_PASSWORD="Password must not have spaces at the beginning or end."
diff --git a/language/en-GB/en-GB.com_users.ini b/language/en-GB/en-GB.com_users.ini
index 9c517367cedcc..71278c17df852 100644
--- a/language/en-GB/en-GB.com_users.ini
+++ b/language/en-GB/en-GB.com_users.ini
@@ -53,10 +53,12 @@ COM_USERS_MAIL_SEND_FAILURE_BODY="An error was encountered when sending the user
 COM_USERS_MAIL_SEND_FAILURE_SUBJECT="Error sending email"
 COM_USERS_MSG_NOT_ENOUGH_INTEGERS_N="Password does not have enough digits. At least %s digits are required."
 COM_USERS_MSG_NOT_ENOUGH_INTEGERS_N_1="Password does not have enough digits. At least 1 digit is required."
+COM_USERS_MSG_NOT_ENOUGH_LOWERCASE_LETTERS_N="Password does not have enough lower case characters. At least %s lower case characters are required."
+COM_USERS_MSG_NOT_ENOUGH_LOWERCASE_LETTERS_N_1="Password does not have enough lower case characters. At least 1 lower case character is required."
 COM_USERS_MSG_NOT_ENOUGH_SYMBOLS_N="Password does not have enough symbols. At least %s symbols are required."
 COM_USERS_MSG_NOT_ENOUGH_SYMBOLS_N_1="Password does not have enough symbols. At least 1 symbol is required."
-COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N="Password does not have enough uppercase characters. At least %s upper case characters are required."
-COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N_1="Password does not have enough uppercase characters. At least 1 upper case character is required."
+COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N="Password does not have enough upper case characters. At least %s upper case characters are required."
+COM_USERS_MSG_NOT_ENOUGH_UPPERCASE_LETTERS_N_1="Password does not have enough upper case characters. At least 1 upper case character is required."
 COM_USERS_MSG_PASSWORD_TOO_LONG="Password is too long. Passwords must be less than 100 characters."
 COM_USERS_MSG_PASSWORD_TOO_SHORT_N="Password is too short. Passwords must have at least %s characters."
 COM_USERS_MSG_SPACES_IN_PASSWORD="Password must not have spaces."
diff --git a/libraries/src/Form/Rule/PasswordRule.php b/libraries/src/Form/Rule/PasswordRule.php
index 3c49715a9b3b4..e311e147013ce 100644
--- a/libraries/src/Form/Rule/PasswordRule.php
+++ b/libraries/src/Form/Rule/PasswordRule.php
@@ -49,6 +49,7 @@ public function test(\SimpleXMLElement $element, $value, $group = null, Registry
 		$minimumIntegers  = isset($element['minimum_integers']) ? (int) $element['minimum_integers'] : 0;
 		$minimumSymbols   = isset($element['minimum_symbols']) ? (int) $element['minimum_symbols'] : 0;
 		$minimumUppercase = isset($element['minimum_uppercase']) ? (int) $element['minimum_uppercase'] : 0;
+		$minimumLowercase = isset($element['minimum_lowercase']) ? (int) $element['minimum_lowercase'] : 0;
 
 		// If we have parameters from com_users, use those instead.
 		// Some of these may be empty for legacy reasons.
@@ -60,6 +61,7 @@ public function test(\SimpleXMLElement $element, $value, $group = null, Registry
 			$minimumIntegersp  = $params->get('minimum_integers');
 			$minimumSymbolsp   = $params->get('minimum_symbols');
 			$minimumUppercasep = $params->get('minimum_uppercase');
+			$minimumLowercasep = $params->get('minimum_lowercase');
 			$meterp            = $params->get('meter');
 			$thresholdp        = $params->get('threshold');
 
@@ -67,6 +69,7 @@ public function test(\SimpleXMLElement $element, $value, $group = null, Registry
 			empty($minimumIntegersp) ? : $minimumIntegers = (int) $minimumIntegersp;
 			empty($minimumSymbolsp) ? : $minimumSymbols = (int) $minimumSymbolsp;
 			empty($minimumUppercasep) ? : $minimumUppercase = (int) $minimumUppercasep;
+			empty($minimumLowercasep) ? : $minimumLowercase = (int) $minimumLowercasep;
 			empty($meterp) ? : $meter = $meterp;
 			empty($thresholdp) ? : $threshold = $thresholdp;
 		}
@@ -154,6 +157,22 @@ public function test(\SimpleXMLElement $element, $value, $group = null, Registry
 			}
 		}
 
+		// Minimum number of lower case ASCII characters required
+		if (!empty($minimumLowercase))
+		{
+			$nLowercase = preg_match_all('/[a-z]/', $value, $umatch);
+
+			if ($nLowercase < $minimumLowercase)
+			{
+				\JFactory::getApplication()->enqueueMessage(
+					\JText::plural('COM_USERS_MSG_NOT_ENOUGH_LOWERCASE_LETTERS_N', $minimumLowercase),
+					'warning'
+				);
+
+				$validPassword = false;
+			}
+		}
+
 		// Minimum length option
 		if (!empty($minimumLength))
 		{