diff --git a/briar-android/src/org/briarproject/android/groups/CreateGroupActivity.java b/briar-android/src/org/briarproject/android/groups/CreateGroupActivity.java
index b0aafeeec..cf33c22ce 100644
--- a/briar-android/src/org/briarproject/android/groups/CreateGroupActivity.java
+++ b/briar-android/src/org/briarproject/android/groups/CreateGroupActivity.java
@@ -14,6 +14,7 @@ import static org.briarproject.android.util.CommonLayoutParams.MATCH_MATCH;
 import static org.briarproject.android.util.CommonLayoutParams.WRAP_WRAP;
 import static org.briarproject.api.messaging.MessagingConstants.MAX_GROUP_NAME_LENGTH;
 
+import java.io.UnsupportedEncodingException;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.concurrent.Executor;
@@ -243,8 +244,13 @@ SelectContactsDialog.Listener {
 	}
 
 	private boolean validateName() {
-		int length = nameEntry.getText().length();
-		if(length == 0 || length > MAX_GROUP_NAME_LENGTH) return false;
+		if(nameEntry.getText().length() == 0) return false;
+		try {
+			byte[] b = nameEntry.getText().toString().getBytes("UTF-8");
+			if(b.length > MAX_GROUP_NAME_LENGTH) return false;
+		} catch(UnsupportedEncodingException e) {
+			throw new RuntimeException(e);
+		}
 		// Hide the soft keyboard
 		Object o = getSystemService(INPUT_METHOD_SERVICE);
 		((InputMethodManager) o).toggleSoftInput(HIDE_IMPLICIT_ONLY, 0);
diff --git a/briar-android/src/org/briarproject/android/identity/CreateIdentityActivity.java b/briar-android/src/org/briarproject/android/identity/CreateIdentityActivity.java
index 117781b1a..05f64cc84 100644
--- a/briar-android/src/org/briarproject/android/identity/CreateIdentityActivity.java
+++ b/briar-android/src/org/briarproject/android/identity/CreateIdentityActivity.java
@@ -14,6 +14,7 @@ import static org.briarproject.android.util.CommonLayoutParams.MATCH_MATCH;
 import static org.briarproject.android.util.CommonLayoutParams.WRAP_WRAP;
 import static org.briarproject.api.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 
+import java.io.UnsupportedEncodingException;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
@@ -136,8 +137,13 @@ implements OnEditorActionListener, OnClickListener {
 	}
 
 	private boolean validateNickname() {
-		int length = nicknameEntry.getText().length();
-		if(length == 0 || length > MAX_AUTHOR_NAME_LENGTH) return false;
+		if(nicknameEntry.getText().length() == 0) return false;
+		try {
+			byte[] b = nicknameEntry.getText().toString().getBytes("UTF-8");
+			if(b.length > MAX_AUTHOR_NAME_LENGTH) return false;
+		} catch(UnsupportedEncodingException e) {
+			throw new RuntimeException(e);
+		}
 		// Hide the soft keyboard
 		Object o = getSystemService(INPUT_METHOD_SERVICE);
 		((InputMethodManager) o).toggleSoftInput(HIDE_IMPLICIT_ONLY, 0);
diff --git a/briar-api/src/org/briarproject/api/Author.java b/briar-api/src/org/briarproject/api/Author.java
index abb66aaa3..16693137b 100644
--- a/briar-api/src/org/briarproject/api/Author.java
+++ b/briar-api/src/org/briarproject/api/Author.java
@@ -2,6 +2,8 @@ package org.briarproject.api;
 
 import static org.briarproject.api.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 
+import java.io.UnsupportedEncodingException;
+
 /** A pseudonym for a user. */
 public class Author {
 
@@ -10,8 +12,13 @@ public class Author {
 	private final byte[] publicKey;
 
 	public Author(AuthorId id, String name, byte[] publicKey) {
-		if(name.length() == 0 || name.length() > MAX_AUTHOR_NAME_LENGTH)
-			throw new IllegalArgumentException();
+		if(name.length() == 0) throw new IllegalArgumentException();
+		try {
+			if(name.getBytes("UTF-8").length > MAX_AUTHOR_NAME_LENGTH)
+				throw new IllegalArgumentException();
+		} catch(UnsupportedEncodingException e) {
+			throw new RuntimeException(e);
+		}
 		this.id = id;
 		this.name = name;
 		this.publicKey = publicKey;
diff --git a/briar-api/src/org/briarproject/api/messaging/Group.java b/briar-api/src/org/briarproject/api/messaging/Group.java
index 882ebbd5b..b7662e276 100644
--- a/briar-api/src/org/briarproject/api/messaging/Group.java
+++ b/briar-api/src/org/briarproject/api/messaging/Group.java
@@ -3,6 +3,8 @@ package org.briarproject.api.messaging;
 import static org.briarproject.api.messaging.MessagingConstants.GROUP_SALT_LENGTH;
 import static org.briarproject.api.messaging.MessagingConstants.MAX_GROUP_NAME_LENGTH;
 
+import java.io.UnsupportedEncodingException;
+
 /** A group to which users may subscribe. */
 public class Group {
 
@@ -11,8 +13,13 @@ public class Group {
 	private final byte[] salt;
 
 	public Group(GroupId id, String name, byte[] salt) {
-		if(name.length() == 0 || name.length() > MAX_GROUP_NAME_LENGTH)
-			throw new IllegalArgumentException();
+		if(name.length() == 0) throw new IllegalArgumentException();
+		try {
+			if(name.getBytes("UTF-8").length > MAX_GROUP_NAME_LENGTH)
+				throw new IllegalArgumentException();
+		} catch(UnsupportedEncodingException e) {
+			throw new RuntimeException(e);
+		}
 		if(salt.length != GROUP_SALT_LENGTH)
 			throw new IllegalArgumentException();
 		this.id = id;