diff --git a/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinter.java b/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinter.java
index a75a483..80f8bb7 100644
--- a/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinter.java
+++ b/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinter.java
@@ -1,3 +1,20 @@
+/*
+ * Copyright (c) 2024 DEC-Dev.
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This code is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this work. If not, see <https://www.gnu.org/licenses/>.
+ */
+
 package org.decdev.thepoetryofwinter;
 
 import net.fabricmc.api.ModInitializer;
diff --git a/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinterClient.java b/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinterClient.java
index 4559766..889b144 100644
--- a/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinterClient.java
+++ b/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinterClient.java
@@ -1,3 +1,20 @@
+/*
+ * Copyright (c) 2024 DEC-Dev.
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This code is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this work. If not, see <https://www.gnu.org/licenses/>.
+ */
+
 package org.decdev.thepoetryofwinter;
 
 import net.fabricmc.api.ClientModInitializer;
diff --git a/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinterDataGenerator.java b/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinterDataGenerator.java
index dff82f5..7e51f8b 100644
--- a/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinterDataGenerator.java
+++ b/src/main/java/org/decdev/thepoetryofwinter/ThePoetryOfWinterDataGenerator.java
@@ -1,3 +1,20 @@
+/*
+ * Copyright (c) 2024 DEC-Dev.
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This code is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this work. If not, see <https://www.gnu.org/licenses/>.
+ */
+
 package org.decdev.thepoetryofwinter;
 
 import net.fabricmc.fabric.api.datagen.v1.DataGeneratorEntrypoint;
diff --git a/src/main/java/org/decdev/thepoetryofwinter/mixin/ExampleMixin.java b/src/main/java/org/decdev/thepoetryofwinter/mixin/ExampleMixin.java
index d5c3eb2..3d23bb8 100644
--- a/src/main/java/org/decdev/thepoetryofwinter/mixin/ExampleMixin.java
+++ b/src/main/java/org/decdev/thepoetryofwinter/mixin/ExampleMixin.java
@@ -1,3 +1,20 @@
+/*
+ * Copyright (c) 2024 DEC-Dev.
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This code is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this work. If not, see <https://www.gnu.org/licenses/>.
+ */
+
 package org.decdev.thepoetryofwinter.mixin;
 
 import net.minecraft.server.MinecraftServer;