diff --git a/build.gradle b/build.gradle
index 064d3e91..6107f256 100644
--- a/build.gradle
+++ b/build.gradle
@@ -4,8 +4,11 @@ plugins {
     id 'maven-publish'
 }
 
-targetCompatibility = JavaVersion.VERSION_16
-sourceCompatibility = JavaVersion.VERSION_16
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(16)
+    }
+}
 
 def createVersion() {
     def parts = []
@@ -59,8 +62,6 @@ dependencies {
     mappings "net.fabricmc:yarn:${project.yarn_mappings}:v2"
     modApi "net.fabricmc:fabric-loader:${project.loader_version}"
 
-    compileOnly "com.google.code.findbugs:jsr305:3.0.2"
-
     modApi fabricApi.module("fabric-api-base", project.fabric_version)
     modApi fabricApi.module("fabric-lifecycle-events-v1", project.fabric_version)
     modApi fabricApi.module("fabric-resource-loader-v0", project.fabric_version)
diff --git a/src/main/java/com/minelittlepony/api/model/armour/IArmourTextureResolver.java b/src/main/java/com/minelittlepony/api/model/armour/IArmourTextureResolver.java
index 249ea7c3..196dcd63 100644
--- a/src/main/java/com/minelittlepony/api/model/armour/IArmourTextureResolver.java
+++ b/src/main/java/com/minelittlepony/api/model/armour/IArmourTextureResolver.java
@@ -5,7 +5,7 @@ import net.minecraft.entity.EquipmentSlot;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.Identifier;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 public interface IArmourTextureResolver {
 
diff --git a/src/main/java/com/minelittlepony/api/model/armour/package-info.java b/src/main/java/com/minelittlepony/api/model/armour/package-info.java
deleted file mode 100644
index d83c4806..00000000
--- a/src/main/java/com/minelittlepony/api/model/armour/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.api.model.armour;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/api/model/fabric/package-info.java b/src/main/java/com/minelittlepony/api/model/fabric/package-info.java
deleted file mode 100644
index 3cef78fe..00000000
--- a/src/main/java/com/minelittlepony/api/model/fabric/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.api.model.fabric;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/api/model/gear/IGear.java b/src/main/java/com/minelittlepony/api/model/gear/IGear.java
index 44752d61..b0509588 100644
--- a/src/main/java/com/minelittlepony/api/model/gear/IGear.java
+++ b/src/main/java/com/minelittlepony/api/model/gear/IGear.java
@@ -11,7 +11,7 @@ import com.minelittlepony.api.model.IModel;
 import com.minelittlepony.api.pony.meta.Wearable;
 import com.minelittlepony.client.render.entity.feature.GearFeature;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.UUID;
 import java.util.function.Supplier;
diff --git a/src/main/java/com/minelittlepony/api/model/gear/package-info.java b/src/main/java/com/minelittlepony/api/model/gear/package-info.java
deleted file mode 100644
index 4b8a0f09..00000000
--- a/src/main/java/com/minelittlepony/api/model/gear/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.api.model.gear;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/api/model/package-info.java b/src/main/java/com/minelittlepony/api/model/package-info.java
deleted file mode 100644
index b455d0ee..00000000
--- a/src/main/java/com/minelittlepony/api/model/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.api.model;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/api/pony/meta/Race.java b/src/main/java/com/minelittlepony/api/pony/meta/Race.java
index 317a61d0..ca315a41 100644
--- a/src/main/java/com/minelittlepony/api/pony/meta/Race.java
+++ b/src/main/java/com/minelittlepony/api/pony/meta/Race.java
@@ -2,7 +2,7 @@ package com.minelittlepony.api.pony.meta;
 
 import com.minelittlepony.api.pony.TriggerPixelType;
 
-import javax.annotation.Nonnull;
+import org.jetbrains.annotations.NotNull;
 
 public enum Race implements TriggerPixelType<Race> {
 
@@ -73,7 +73,7 @@ public enum Race implements TriggerPixelType<Race> {
      * Gets the original race that this one is an alias for, if one exists.
      * Otherwise returns this race.
      */
-    @Nonnull
+    @NotNull
     public Race getAlias() {
         return original;
     }
diff --git a/src/main/java/com/minelittlepony/api/pony/meta/package-info.java b/src/main/java/com/minelittlepony/api/pony/meta/package-info.java
deleted file mode 100644
index fec360a6..00000000
--- a/src/main/java/com/minelittlepony/api/pony/meta/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.api.pony.meta;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/api/pony/network/package-info.java b/src/main/java/com/minelittlepony/api/pony/network/package-info.java
deleted file mode 100644
index 452cf392..00000000
--- a/src/main/java/com/minelittlepony/api/pony/network/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.api.pony.network;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/api/pony/package-info.java b/src/main/java/com/minelittlepony/api/pony/package-info.java
deleted file mode 100644
index b83ba342..00000000
--- a/src/main/java/com/minelittlepony/api/pony/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.api.pony;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/GuiPonySettings.java b/src/main/java/com/minelittlepony/client/GuiPonySettings.java
index 94cc309b..917f436b 100644
--- a/src/main/java/com/minelittlepony/client/GuiPonySettings.java
+++ b/src/main/java/com/minelittlepony/client/GuiPonySettings.java
@@ -18,7 +18,7 @@ import com.minelittlepony.common.client.gui.element.Slider;
 import com.minelittlepony.common.client.gui.element.Toggle;
 import com.minelittlepony.common.util.settings.Setting;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * In-Game options menu.
diff --git a/src/main/java/com/minelittlepony/client/SkinsProxy.java b/src/main/java/com/minelittlepony/client/SkinsProxy.java
index 8e4a0cd4..0f30ea1b 100644
--- a/src/main/java/com/minelittlepony/client/SkinsProxy.java
+++ b/src/main/java/com/minelittlepony/client/SkinsProxy.java
@@ -13,7 +13,7 @@ import net.minecraft.client.network.AbstractClientPlayerEntity;
 import net.minecraft.client.texture.PlayerSkinProvider;
 import net.minecraft.util.Identifier;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 public class SkinsProxy {
 
diff --git a/src/main/java/com/minelittlepony/client/hdskins/MineLPHDSkins.java b/src/main/java/com/minelittlepony/client/hdskins/MineLPHDSkins.java
index 3cee42ec..e3790231 100644
--- a/src/main/java/com/minelittlepony/client/hdskins/MineLPHDSkins.java
+++ b/src/main/java/com/minelittlepony/client/hdskins/MineLPHDSkins.java
@@ -16,7 +16,7 @@ import com.minelittlepony.hdskins.profile.SkinType;
 
 import com.mojang.authlib.GameProfile;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 import net.fabricmc.api.ClientModInitializer;
 import net.minecraft.client.MinecraftClient;
diff --git a/src/main/java/com/minelittlepony/client/hdskins/package-info.java b/src/main/java/com/minelittlepony/client/hdskins/package-info.java
deleted file mode 100644
index 9ae247af..00000000
--- a/src/main/java/com/minelittlepony/client/hdskins/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.hdskins;
-
-import javax.annotation.ParametersAreNonnullByDefault;
\ No newline at end of file
diff --git a/src/main/java/com/minelittlepony/client/mixin/MixinFirstPersonRenderer.java b/src/main/java/com/minelittlepony/client/mixin/MixinFirstPersonRenderer.java
index d7a2374c..ba05ccf8 100644
--- a/src/main/java/com/minelittlepony/client/mixin/MixinFirstPersonRenderer.java
+++ b/src/main/java/com/minelittlepony/client/mixin/MixinFirstPersonRenderer.java
@@ -6,7 +6,7 @@ import org.spongepowered.asm.mixin.injection.Redirect;
 
 import com.minelittlepony.client.render.PonyRenderDispatcher;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 import net.minecraft.client.render.item.HeldItemRenderer;
 import net.minecraft.client.render.VertexConsumerProvider;
diff --git a/src/main/java/com/minelittlepony/client/mixin/MixinSkullBlockEntityRenderer.java b/src/main/java/com/minelittlepony/client/mixin/MixinSkullBlockEntityRenderer.java
index 42ce37d6..44f3b7e9 100644
--- a/src/main/java/com/minelittlepony/client/mixin/MixinSkullBlockEntityRenderer.java
+++ b/src/main/java/com/minelittlepony/client/mixin/MixinSkullBlockEntityRenderer.java
@@ -19,7 +19,7 @@ import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 import com.minelittlepony.client.render.blockentity.skull.PonySkullRenderer;
 import com.mojang.authlib.GameProfile;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 @Mixin(SkullBlockEntityRenderer.class)
 abstract class MixinSkullBlockEntityRenderer implements BlockEntityRenderer<SkullBlockEntity> {
diff --git a/src/main/java/com/minelittlepony/client/mixin/package-info.java b/src/main/java/com/minelittlepony/client/mixin/package-info.java
deleted file mode 100644
index 7aff3b4b..00000000
--- a/src/main/java/com/minelittlepony/client/mixin/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.mixin;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/model/ModelType.java b/src/main/java/com/minelittlepony/client/model/ModelType.java
index da7e6b8d..da25dfe5 100644
--- a/src/main/java/com/minelittlepony/client/model/ModelType.java
+++ b/src/main/java/com/minelittlepony/client/model/ModelType.java
@@ -43,7 +43,7 @@ import com.minelittlepony.mson.api.ModelKey;
 import com.minelittlepony.mson.api.Mson;
 import com.minelittlepony.mson.api.MsonModel;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.HashMap;
 import java.util.Map;
diff --git a/src/main/java/com/minelittlepony/client/model/armour/DefaultArmourTextureResolver.java b/src/main/java/com/minelittlepony/client/model/armour/DefaultArmourTextureResolver.java
index 9bb5b68c..4e0917be 100644
--- a/src/main/java/com/minelittlepony/client/model/armour/DefaultArmourTextureResolver.java
+++ b/src/main/java/com/minelittlepony/client/model/armour/DefaultArmourTextureResolver.java
@@ -14,7 +14,7 @@ import com.minelittlepony.api.model.armour.ArmourVariant;
 import com.minelittlepony.api.model.armour.IArmourTextureResolver;
 import com.minelittlepony.util.ResourceUtil;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 import java.nio.file.Path;
 import java.nio.file.Paths;
diff --git a/src/main/java/com/minelittlepony/client/model/armour/package-info.java b/src/main/java/com/minelittlepony/client/model/armour/package-info.java
deleted file mode 100644
index 719ffa43..00000000
--- a/src/main/java/com/minelittlepony/client/model/armour/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.model.armour;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/model/entity/package-info.java b/src/main/java/com/minelittlepony/client/model/entity/package-info.java
deleted file mode 100644
index 77d91b35..00000000
--- a/src/main/java/com/minelittlepony/client/model/entity/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.model.entity;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/model/entity/race/package-info.java b/src/main/java/com/minelittlepony/client/model/entity/race/package-info.java
deleted file mode 100644
index f5041cfa..00000000
--- a/src/main/java/com/minelittlepony/client/model/entity/race/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.model.entity.race;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/model/gear/package-info.java b/src/main/java/com/minelittlepony/client/model/gear/package-info.java
deleted file mode 100644
index 191d9195..00000000
--- a/src/main/java/com/minelittlepony/client/model/gear/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.model.gear;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/model/package-info.java b/src/main/java/com/minelittlepony/client/model/package-info.java
deleted file mode 100644
index a5ea628f..00000000
--- a/src/main/java/com/minelittlepony/client/model/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.model;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/model/part/UnicornHorn.java b/src/main/java/com/minelittlepony/client/model/part/UnicornHorn.java
index 560e8e99..fcf59436 100644
--- a/src/main/java/com/minelittlepony/client/model/part/UnicornHorn.java
+++ b/src/main/java/com/minelittlepony/client/model/part/UnicornHorn.java
@@ -13,7 +13,7 @@ import com.minelittlepony.common.util.Color;
 import com.minelittlepony.mson.api.ModelContext;
 import com.minelittlepony.mson.api.MsonModel;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.UUID;
 
diff --git a/src/main/java/com/minelittlepony/client/model/part/package-info.java b/src/main/java/com/minelittlepony/client/model/part/package-info.java
deleted file mode 100644
index 8af3241d..00000000
--- a/src/main/java/com/minelittlepony/client/model/part/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.model.part;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/package-info.java b/src/main/java/com/minelittlepony/client/package-info.java
deleted file mode 100644
index c177b8c5..00000000
--- a/src/main/java/com/minelittlepony/client/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/pony/NativePonyData.java b/src/main/java/com/minelittlepony/client/pony/NativePonyData.java
index 5026014a..481d1cd7 100644
--- a/src/main/java/com/minelittlepony/client/pony/NativePonyData.java
+++ b/src/main/java/com/minelittlepony/client/pony/NativePonyData.java
@@ -21,12 +21,12 @@ import java.util.Map;
 import java.util.TreeMap;
 import java.util.UUID;
 
-import javax.annotation.concurrent.Immutable;
+import org.jetbrains.annotations.Unmodifiable;
 
 /**
  * Implementation for IPonyData.
  */
-@Immutable
+@Unmodifiable
 class NativePonyData implements IPonyData {
     private final TriggerPixelValue<Race> race;
     private final TriggerPixelValue<TailLength> tailSize;
diff --git a/src/main/java/com/minelittlepony/client/pony/Pony.java b/src/main/java/com/minelittlepony/client/pony/Pony.java
index 0dbf6a93..d61c67fb 100644
--- a/src/main/java/com/minelittlepony/client/pony/Pony.java
+++ b/src/main/java/com/minelittlepony/client/pony/Pony.java
@@ -29,9 +29,9 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.MathHelper;
 import net.minecraft.util.math.Vec3d;
 
-import javax.annotation.concurrent.Immutable;
+import org.jetbrains.annotations.Unmodifiable;
 
-@Immutable
+@Unmodifiable
 public class Pony implements IPony {
 
     private final Identifier texture;
diff --git a/src/main/java/com/minelittlepony/client/pony/PonyData.java b/src/main/java/com/minelittlepony/client/pony/PonyData.java
index 1c11b7ec..7414af93 100644
--- a/src/main/java/com/minelittlepony/client/pony/PonyData.java
+++ b/src/main/java/com/minelittlepony/client/pony/PonyData.java
@@ -22,13 +22,13 @@ import java.util.Map;
 import java.util.TreeMap;
 import java.util.UUID;
 
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.Immutable;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.Unmodifiable;
 
 /**
  * Implementation for IPonyData.
  */
-@Immutable
+@Unmodifiable
 public class PonyData implements IPonyData {
 
     private static final PonyDataSerialiser SERIALISER = new PonyDataSerialiser();
diff --git a/src/main/java/com/minelittlepony/client/pony/PonyManager.java b/src/main/java/com/minelittlepony/client/pony/PonyManager.java
index 7ce362fb..13f44012 100644
--- a/src/main/java/com/minelittlepony/client/pony/PonyManager.java
+++ b/src/main/java/com/minelittlepony/client/pony/PonyManager.java
@@ -8,7 +8,7 @@ import com.minelittlepony.api.pony.IPonyManager;
 import com.minelittlepony.client.MineLittlePony;
 import com.minelittlepony.settings.PonyConfig;
 import com.minelittlepony.settings.PonyLevel;
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 import net.fabricmc.fabric.api.resource.IdentifiableResourceReloadListener;
 import net.minecraft.client.network.AbstractClientPlayerEntity;
diff --git a/src/main/java/com/minelittlepony/client/pony/package-info.java b/src/main/java/com/minelittlepony/client/pony/package-info.java
deleted file mode 100644
index 44794b26..00000000
--- a/src/main/java/com/minelittlepony/client/pony/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.pony;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/render/EquineRenderManager.java b/src/main/java/com/minelittlepony/client/render/EquineRenderManager.java
index 3c373451..bb3c9054 100644
--- a/src/main/java/com/minelittlepony/client/render/EquineRenderManager.java
+++ b/src/main/java/com/minelittlepony/client/render/EquineRenderManager.java
@@ -12,7 +12,7 @@ import com.mojang.blaze3d.platform.GlStateManager.DstFactor;
 import com.mojang.blaze3d.platform.GlStateManager.SrcFactor;
 import com.mojang.blaze3d.systems.RenderSystem;
 
-import javax.annotation.Nonnull;
+import org.jetbrains.annotations.NotNull;
 
 import net.minecraft.client.render.Frustum;
 import net.minecraft.client.render.entity.model.EntityModel;
@@ -107,7 +107,7 @@ public class EquineRenderManager<T extends LivingEntity, M extends EntityModel<T
         ((PonyPosture<T>) getPosture(player)).apply(player, getModel(), stack, yaw, ticks, -1);
     }
 
-    @Nonnull
+    @NotNull
     private PonyPosture<?> getPosture(T entity) {
         if (entity.isFallFlying()) {
             return PonyPosture.ELYTRA;
diff --git a/src/main/java/com/minelittlepony/client/render/LevitatingItemRenderer.java b/src/main/java/com/minelittlepony/client/render/LevitatingItemRenderer.java
index 1c66c4a1..ca4c9838 100644
--- a/src/main/java/com/minelittlepony/client/render/LevitatingItemRenderer.java
+++ b/src/main/java/com/minelittlepony/client/render/LevitatingItemRenderer.java
@@ -4,7 +4,7 @@ import com.minelittlepony.api.pony.IPony;
 import com.minelittlepony.client.MineLittlePony;
 import com.minelittlepony.common.util.Color;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 import net.minecraft.client.MinecraftClient;
 import net.minecraft.client.render.OverlayTexture;
diff --git a/src/main/java/com/minelittlepony/client/render/PonyRenderDispatcher.java b/src/main/java/com/minelittlepony/client/render/PonyRenderDispatcher.java
index 486d5c2d..878dee15 100644
--- a/src/main/java/com/minelittlepony/client/render/PonyRenderDispatcher.java
+++ b/src/main/java/com/minelittlepony/client/render/PonyRenderDispatcher.java
@@ -7,7 +7,7 @@ import com.google.common.collect.Maps;
 import com.minelittlepony.client.model.IPonyModel;
 import com.minelittlepony.client.model.entity.race.PlayerModels;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 import com.minelittlepony.common.mixin.MixinEntityRenderDispatcher;
 import com.minelittlepony.mson.api.Mson;
diff --git a/src/main/java/com/minelittlepony/client/render/blockentity/skull/MobSkull.java b/src/main/java/com/minelittlepony/client/render/blockentity/skull/MobSkull.java
index 0505e319..1cc767c5 100644
--- a/src/main/java/com/minelittlepony/client/render/blockentity/skull/MobSkull.java
+++ b/src/main/java/com/minelittlepony/client/render/blockentity/skull/MobSkull.java
@@ -5,7 +5,7 @@ import com.minelittlepony.settings.PonyConfig;
 import com.mojang.authlib.GameProfile;
 import net.minecraft.util.Identifier;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 public class MobSkull extends AbstractPonySkull {
 
diff --git a/src/main/java/com/minelittlepony/client/render/blockentity/skull/PonySkull.java b/src/main/java/com/minelittlepony/client/render/blockentity/skull/PonySkull.java
index 93cc7ae5..6d9ba56a 100644
--- a/src/main/java/com/minelittlepony/client/render/blockentity/skull/PonySkull.java
+++ b/src/main/java/com/minelittlepony/client/render/blockentity/skull/PonySkull.java
@@ -13,7 +13,7 @@ import net.minecraft.client.util.math.MatrixStack;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.util.Identifier;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 public class PonySkull extends AbstractPonySkull {
 
diff --git a/src/main/java/com/minelittlepony/client/render/blockentity/skull/PonySkullRenderer.java b/src/main/java/com/minelittlepony/client/render/blockentity/skull/PonySkullRenderer.java
index 341c5128..72319db2 100644
--- a/src/main/java/com/minelittlepony/client/render/blockentity/skull/PonySkullRenderer.java
+++ b/src/main/java/com/minelittlepony/client/render/blockentity/skull/PonySkullRenderer.java
@@ -21,7 +21,7 @@ import net.minecraft.util.Util;
 import net.minecraft.util.math.Direction;
 
 import java.util.Map;
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * PonySkullRenderer! It renders ponies as skulls, or something...
diff --git a/src/main/java/com/minelittlepony/client/render/blockentity/skull/package-info.java b/src/main/java/com/minelittlepony/client/render/blockentity/skull/package-info.java
deleted file mode 100644
index 771a4e68..00000000
--- a/src/main/java/com/minelittlepony/client/render/blockentity/skull/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.render.blockentity.skull;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/render/entity/PonyRenderer.java b/src/main/java/com/minelittlepony/client/render/entity/PonyRenderer.java
index b69bf7bb..02abd6c3 100644
--- a/src/main/java/com/minelittlepony/client/render/entity/PonyRenderer.java
+++ b/src/main/java/com/minelittlepony/client/render/entity/PonyRenderer.java
@@ -30,7 +30,7 @@ import net.minecraft.text.Text;
 import net.minecraft.util.Identifier;
 
 import java.util.List;
-import javax.annotation.Nonnull;
+import org.jetbrains.annotations.NotNull;
 
 public abstract class PonyRenderer<T extends MobEntity, M extends EntityModel<T> & IPonyModel<T>> extends MobEntityRenderer<T, M> implements IPonyRenderContext<T, M> {
 
@@ -113,7 +113,7 @@ public abstract class PonyRenderer<T extends MobEntity, M extends EntityModel<T>
 
     @Deprecated
     @Override
-    @Nonnull
+    @NotNull
     public final Identifier getTexture(T entity) {
         return findTexture(entity);
     }
diff --git a/src/main/java/com/minelittlepony/client/render/entity/SeaponyRenderer.java b/src/main/java/com/minelittlepony/client/render/entity/SeaponyRenderer.java
index 288f9cdf..dfc8bc43 100644
--- a/src/main/java/com/minelittlepony/client/render/entity/SeaponyRenderer.java
+++ b/src/main/java/com/minelittlepony/client/render/entity/SeaponyRenderer.java
@@ -1,6 +1,6 @@
 package com.minelittlepony.client.render.entity;
 
-import javax.annotation.Nonnull;
+import org.jetbrains.annotations.NotNull;
 
 import com.minelittlepony.client.mixin.IResizeable;
 import com.minelittlepony.client.model.ModelType;
@@ -43,7 +43,7 @@ public class SeaponyRenderer extends GuardianEntityRenderer {
     }
 
     @Override
-    @Nonnull
+    @NotNull
     public final Identifier getTexture(GuardianEntity entity) {
         return ponyRenderer.getTextureFor(entity);
     }
diff --git a/src/main/java/com/minelittlepony/client/render/entity/feature/package-info.java b/src/main/java/com/minelittlepony/client/render/entity/feature/package-info.java
deleted file mode 100644
index 72de15a1..00000000
--- a/src/main/java/com/minelittlepony/client/render/entity/feature/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.render.entity.feature;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/render/entity/package-info.java b/src/main/java/com/minelittlepony/client/render/entity/package-info.java
deleted file mode 100644
index 11643dfa..00000000
--- a/src/main/java/com/minelittlepony/client/render/entity/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.render.entity;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/render/package-info.java b/src/main/java/com/minelittlepony/client/render/package-info.java
deleted file mode 100644
index 4414b602..00000000
--- a/src/main/java/com/minelittlepony/client/render/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.render;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/settings/package-info.java b/src/main/java/com/minelittlepony/client/settings/package-info.java
deleted file mode 100644
index a2026d44..00000000
--- a/src/main/java/com/minelittlepony/client/settings/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.settings;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/client/transform/package-info.java b/src/main/java/com/minelittlepony/client/transform/package-info.java
deleted file mode 100644
index 4c04e3b7..00000000
--- a/src/main/java/com/minelittlepony/client/transform/package-info.java
+++ /dev/null
@@ -1,5 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.transform;
-
-import javax.annotation.ParametersAreNonnullByDefault;
-
diff --git a/src/main/java/com/minelittlepony/client/util/render/package-info.java b/src/main/java/com/minelittlepony/client/util/render/package-info.java
deleted file mode 100644
index 4b1036d0..00000000
--- a/src/main/java/com/minelittlepony/client/util/render/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.client.util.render;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/settings/package-info.java b/src/main/java/com/minelittlepony/settings/package-info.java
deleted file mode 100644
index f4dfe2cc..00000000
--- a/src/main/java/com/minelittlepony/settings/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.settings;
-
-import javax.annotation.ParametersAreNonnullByDefault;
diff --git a/src/main/java/com/minelittlepony/util/package-info.java b/src/main/java/com/minelittlepony/util/package-info.java
deleted file mode 100644
index af939ba7..00000000
--- a/src/main/java/com/minelittlepony/util/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-@ParametersAreNonnullByDefault
-package com.minelittlepony.util;
-
-import javax.annotation.ParametersAreNonnullByDefault;