diff --git a/perun-wui-core/src/main/java/cz/metacentrum/perun/wui/client/resources/PerunTranslation.java b/perun-wui-core/src/main/java/cz/metacentrum/perun/wui/client/resources/PerunTranslation.java
index 8909b569..6126387d 100644
--- a/perun-wui-core/src/main/java/cz/metacentrum/perun/wui/client/resources/PerunTranslation.java
+++ b/perun-wui-core/src/main/java/cz/metacentrum/perun/wui/client/resources/PerunTranslation.java
@@ -288,4 +288,13 @@ public interface PerunTranslation extends Messages {
 	@DefaultMessage("Password <b>can`t contain login, name or surname</b>, not even backwards!")
 	public String einfraPasswordStrengthForNameLogin();
 
+	@DefaultMessage("Password must <ul><li>be at least 12 characters long<li>consist of at least 3 of 4 character groups<ul><li>lower-case letters<li>upper-case letters<li>digits<li>special characters</ul></ul>")
+	public String muPasswordHelp();
+
+	@DefaultMessage("Password must be <b>at least 12 characters</b> long!")
+	public String muPasswordLength();
+
+	@DefaultMessage("Password must consist of <b>at least 3 of 4</b> character groups<ul><li>lower-case letters</li><li>upper-case letters</li><li>digits</li><li>special characters</li></ul>")
+	public String muPasswordStrength();
+
 }
diff --git a/perun-wui-core/src/main/resources/cz/metacentrum/perun/wui/client/resources/PerunTranslation_cs.properties b/perun-wui-core/src/main/resources/cz/metacentrum/perun/wui/client/resources/PerunTranslation_cs.properties
index 328e951b..8977fdac 100644
--- a/perun-wui-core/src/main/resources/cz/metacentrum/perun/wui/client/resources/PerunTranslation_cs.properties
+++ b/perun-wui-core/src/main/resources/cz/metacentrum/perun/wui/client/resources/PerunTranslation_cs.properties
@@ -104,3 +104,6 @@ einfraPasswordLength=Heslo musí mít <b>alespoň 10 znaků!</b>
 einfraPasswordFormat=Heslo <b>nesmí obsahovat diakritiku</b> nebo řídící a formátovací znaky!</b>
 einfraPasswordStrength=Heslo musí obsahovat <b>alespoň 3 ze 4</b> kategorií znaků<ul><li>malá písmena</li><li>velká písmena</li><li>číslice</li><li>speciální znaky</li></ul>
 einfraPasswordStrengthForNameLogin=Heslo <b>nesmí obsahovat login, jméno nebo příjmení</b> a to ani pozpátku!
+muPasswordHelp=Heslo musí<ul><li>mít délku 12 a více znaků<li>obsahovat alespoň 3 ze 4 kategorií znaků<ul><li>malá písmena<li>velká písmena<li>číslice<li>speciální znaky</ul></ul>
+muPasswordLength=Heslo musí mít <b>alespoň 12 znaků!</b>
+muPasswordStrength=Heslo musí obsahovat <b>alespoň 3 ze 4</b> kategorií znaků<ul><li>malá písmena</li><li>velká písmena</li><li>číslice</li><li>speciální znaky</li></ul>
diff --git a/perun-wui-pwdreset/src/main/java/cz/metacentrum/perun/wui/pwdreset/pages/PwdResetView.java b/perun-wui-pwdreset/src/main/java/cz/metacentrum/perun/wui/pwdreset/pages/PwdResetView.java
index 929ae2c3..914775e3 100644
--- a/perun-wui-pwdreset/src/main/java/cz/metacentrum/perun/wui/pwdreset/pages/PwdResetView.java
+++ b/perun-wui-pwdreset/src/main/java/cz/metacentrum/perun/wui/pwdreset/pages/PwdResetView.java
@@ -348,6 +348,8 @@ public void onFinished(JavaScriptObject result) {
 									help.setHTML("<p>" + translation.einfraPasswordHelp());
 								} else if (Objects.equals(namespace, "vsup")) {
 									help.setHTML("<p>"+translation.vsupHelp());
+								} else if (Objects.equals(namespace, "mu")) {
+									help.setHTML("<p>"+translation.muPasswordHelp());
 								}
 
 								return;
@@ -509,6 +511,34 @@ private boolean validate() {
 				return false;
 			}
 
+		} else if (Objects.equals(namespace, "mu")) {
+
+			// Check that password contains at least 3 of 4 character groups
+
+			RegExp regExpDigit = RegExp.compile("^.*[0-9].*$");
+			RegExp regExpLower = RegExp.compile("^.*[a-z].*$");
+			RegExp regExpUpper = RegExp.compile("^.*[A-Z].*$");
+			RegExp regExpSpec = RegExp.compile("^.*[\\x20-\\x2F\\x3A-\\x40\\x5B-\\x60\\x7B-\\x7E].*$"); // FIXME - are those correct printable specific chars?
+
+			int matchCounter = 0;
+			if (regExpDigit.exec(passwordTextBox.getValue()) != null) matchCounter++;
+			if (regExpLower.exec(passwordTextBox.getValue()) != null) matchCounter++;
+			if (regExpUpper.exec(passwordTextBox.getValue()) != null) matchCounter++;
+			if (regExpSpec.exec(passwordTextBox.getValue()) != null) matchCounter++;
+
+			if(matchCounter < 3){
+				passItem.setValidationState(ValidationState.ERROR);
+				itemStatus.setHTML(translation.muPasswordStrength());
+				return false;
+			}
+
+			// check length
+			if (passwordTextBox.getValue().length() < 12) {
+				passItem.setValidationState(ValidationState.ERROR);
+				itemStatus.setHTML(translation.muPasswordLength());
+				return false;
+			}
+
 		}
 
 		if (!Objects.equals(passwordTextBox.getValue(), passwordTextBox2.getValue())) {