diff --git a/src/main/java/dev/logal/logalbot/commands/CommandResponse.java b/src/main/java/dev/logal/logalbot/commands/CommandResponse.java
index e9b35e6..37d867a 100644
--- a/src/main/java/dev/logal/logalbot/commands/CommandResponse.java
+++ b/src/main/java/dev/logal/logalbot/commands/CommandResponse.java
@@ -31,6 +31,7 @@ import net.dv8tion.jda.core.entities.Message;
 import net.dv8tion.jda.core.entities.MessageEmbed;
 import net.dv8tion.jda.core.entities.TextChannel;
 import net.dv8tion.jda.core.entities.User;
+import net.dv8tion.jda.core.utils.Checks;
 
 public final class CommandResponse {
     private final Emoji emoji;
@@ -43,38 +44,56 @@ public final class CommandResponse {
     private TimeUnit deletionDelayUnit, expireDelayUnit;
 
     public CommandResponse(final String emoji, final String response) {
+        Checks.notNull(emoji, "Emoji");
+        Checks.notNull(response, "Response");
+
         this.emoji = EmojiManager.getForAlias(emoji);
         this.response = response;
     }
 
     public final CommandResponse attachEmbed(final MessageEmbed embed) {
+        Checks.notNull(embed, "Embed");
+
         this.responseEmbed = embed;
         return this;
     }
 
     public final CommandResponse setDeletionDelay(final long delay, final TimeUnit unit) {
+        Checks.notNull(delay, "Delay");
+        Checks.notNull(unit, "Unit");
+
         this.deletionDelay = delay;
         this.deletionDelayUnit = unit;
         return this;
     }
 
     public final CommandResponse addReactionCallback(final String emoji, final ReactionCallback callback) {
+        Checks.notNull(emoji, "Emoji");
+        Checks.notNull(callback, "Callback");
+
         this.callbacks.put(EmojiManager.getForAlias(emoji), callback);
         return this;
     }
 
     public final CommandResponse setReactionCallbackTarget(final Member member) {
+        Checks.notNull(member, "Member");
+
         this.callbacksTarget = member.getUser();
         return this;
     }
 
     public final CommandResponse setReactionCallbackExpireDelay(final long delay, final TimeUnit unit) {
+        Checks.notNull(delay, "Delay");
+        Checks.notNull(unit, "Unit");
+
         this.expireDelay = delay;
         this.expireDelayUnit = unit;
         return this;
     }
 
     public final void sendResponse(final TextChannel channel) {
+        Checks.notNull(channel, "Channel");
+
         final MessageBuilder builder = new MessageBuilder();
         builder.setContent(this.emoji.getUnicode() + " " + this.response);