diff --git a/includes/Channel.hpp b/includes/Channel.hpp
index 3f7cc15..9807146 100644
--- a/includes/Channel.hpp
+++ b/includes/Channel.hpp
@@ -7,7 +7,7 @@
 # include "User.hpp"
 
 # define MAX_CHANNEL_NAME_LENGTH 20
-# define NO_LIMIT -1
+# define NO_LIMIT 0
 # define BELL_CHAR '\a'
 
 class User;
diff --git a/src/Channel.cpp b/src/Channel.cpp
index 975625d..1005777 100644
--- a/src/Channel.cpp
+++ b/src/Channel.cpp
@@ -260,7 +260,7 @@ bool Channel::hasLimit() const {
  * @return `true` if the channel is full, `false` otherwise.
  */
 bool Channel::isFull() const {
-    return (int) (this->_users.size() + this->_operators.size()) == this->_limit;
+    return (int) (this->_users.size() + this->_operators.size()) >= this->_limit && this->_limit != NO_LIMIT;
 }
 
 /**
diff --git a/src/Utils.cpp b/src/Utils.cpp
index e5067ba..83a905d 100644
--- a/src/Utils.cpp
+++ b/src/Utils.cpp
@@ -39,7 +39,7 @@ std::vector<std::string> Utils::split(const std::string &s, char delim) {
 bool Utils::isNumber(const std::string& s) {
     std::string::const_iterator it = s.begin();
     
-    while (it != s.end() && std::isdigit(*it))
+    while (it != s.end() && (std::isdigit(*it) || (*it == '-' && it == s.begin())))
         ++it;
     return !s.empty() && it == s.end();
 }
\ No newline at end of file
diff --git a/src/commands/ModeCommand.cpp b/src/commands/ModeCommand.cpp
index f0f1297..f832e8f 100644
--- a/src/commands/ModeCommand.cpp
+++ b/src/commands/ModeCommand.cpp
@@ -58,36 +58,31 @@ void ModeCommand::execute(int clientFd) {
     std::string flag = _plus ? "+" : "-";
     std::vector<std::string>::iterator paramIterator = _modeParams.begin();
     std::string param = NONE;
+    std::string modeParams = NONE;
     for (size_t i = 0; i < _modes.size(); i++) {
         flag += _modes[i];
-    
+        
         if (ModeCommand::modeNeedsParam(_modes[i])) {
             if (paramIterator == _modeParams.end())
                 throw NeedMoreParamsException("MODE");
             param = *(paramIterator++);
+            modeParams += param + " ";
         }
-        switch (_modes[i]) {
-            case INVITE_ONLY:
-                ModeCommand::inviteOnly();
-                break;
-            case TOPIC_PROTECTED:
-                ModeCommand::topicProtected();
-                break;
-            case CHANNEL_KEY:
-                ModeCommand::channelKey(param);
-                break;
-            case CHANNEL_OPERATOR:
-                ModeCommand::channelOperator(param);
-                break;
-            case USER_LIMIT:
-                ModeCommand::userLimit(param);
-                break;
-            default:
-                throw UnknownModeException(std::string(1, _modes[i]));
+        try {
+            switch (_modes[i]) {
+                case INVITE_ONLY:       ModeCommand::inviteOnly(); break;
+                case TOPIC_PROTECTED:   ModeCommand::topicProtected(); break;
+                case CHANNEL_KEY:       ModeCommand::channelKey(param); break;
+                case CHANNEL_OPERATOR:  ModeCommand::channelOperator(param); break;
+                case USER_LIMIT:        ModeCommand::userLimit(param); break;
+                default:                throw UnknownModeException(std::string(1, _modes[i]));
+            }
+        } catch (IRCException &e) {
+            server.sendExceptionMessage(clientFd, e);
         }
     }
     _channel.broadcastToChannel(
-        CMD_MSG(me.getNickname(), me.getUsername(), me.getHostname(), MODE_MSG(_channel.getName(), flag, param))
+        CMD_MSG(me.getNickname(), me.getUsername(), me.getHostname(), MODE_MSG(_channel.getName(), flag, modeParams))
     );
 }
 
@@ -129,6 +124,7 @@ void ModeCommand::channelKey(const std::string & param) {
  * Sets the user as an operator of the channel.
  */
 void ModeCommand::channelOperator(const std::string &param) {
+    Server::getInstance().getUserByNickname(param);
     if (!_channel.isUserInChannel(param))
         throw UserNotInChannelException(param, _channel.getName());
     if (_plus)