diff --git a/src/integration-test/kotlin/de/bixilon/minosoft/protocol/packets/s2c/play/InitializeS2CPTest.kt b/src/integration-test/kotlin/de/bixilon/minosoft/protocol/packets/s2c/play/InitializeS2CPTest.kt
new file mode 100644
index 000000000..f6db43af1
--- /dev/null
+++ b/src/integration-test/kotlin/de/bixilon/minosoft/protocol/packets/s2c/play/InitializeS2CPTest.kt
@@ -0,0 +1,61 @@
+/*
+ * Minosoft
+ * Copyright (C) 2020-2023 Moritz Zwerger
+ *
+ * This program 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 program 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 program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * This software is not affiliated with Mojang AB, the original developer of Minecraft.
+ */
+
+package de.bixilon.minosoft.protocol.packets.s2c.play
+
+import de.bixilon.minosoft.data.abilities.Gamemodes
+import de.bixilon.minosoft.data.registries.dimension.effects.OverworldEffects
+import org.testng.Assert.*
+import org.testng.annotations.Test
+
+@Test(groups = ["packet"])
+class InitializeS2CPTest {
+
+    fun vanilla_1_15_2() {
+        val packet = PacketReadingTestUtil.read("initialize/vanilla_1_15_2", "1.15.2", constructor = ::InitializeS2CP)
+        assertEquals(packet.gamemode, Gamemodes.SURVIVAL)
+        assertEquals(packet.dimension?.effects, OverworldEffects)
+        assertEquals(packet.entityId, 424)
+        assertEquals(packet.viewDistance, 9)
+    }
+
+    fun vanilla_1_16_5() {
+        val packet = PacketReadingTestUtil.read("initialize/vanilla_1_16_5", "1.16.5", constructor = ::InitializeS2CP)
+        assertEquals(packet.gamemode, Gamemodes.CREATIVE)
+        assertEquals(packet.dimension?.effects, OverworldEffects)
+        assertEquals(packet.entityId, 321)
+        assertEquals(packet.viewDistance, 8)
+        assertEquals(packet.registries?.size, 2)
+        assertTrue(packet.registries!!["minecraft:worldgen/biome"] is Map<*, *>)
+    }
+
+    fun hypixel_1_19_4() {
+        val packet = PacketReadingTestUtil.read("initialize/hypixel_1_19_4", "1.19.4", constructor = ::InitializeS2CP)
+        assertEquals(packet.gamemode, Gamemodes.SURVIVAL)
+        assertEquals(packet.dimensionName, OverworldEffects.identifier)
+        assertEquals(packet.entityId, 11659106)
+        assertNull(packet.lastDeathPosition)
+        assertEquals(packet.registries?.size, 6)
+        assertTrue(packet.registries!!["minecraft:worldgen/biome"] is Map<*, *>)
+    }
+
+    fun vanilla_1_20_1() {
+        val packet = PacketReadingTestUtil.read("initialize/vanilla_1_20_1", "1.20.1", constructor = ::InitializeS2CP)
+        assertEquals(packet.gamemode, Gamemodes.CREATIVE)
+        assertEquals(packet.dimensionName, OverworldEffects.identifier)
+        assertNull(packet.lastDeathPosition)
+        assertEquals(packet.registries?.size, 6)
+        assertTrue(packet.registries!!["minecraft:worldgen/biome"] is Map<*, *>)
+    }
+}
+
diff --git a/src/integration-test/kotlin/de/bixilon/minosoft/protocol/packets/s2c/play/PacketReadingTestUtil.kt b/src/integration-test/kotlin/de/bixilon/minosoft/protocol/packets/s2c/play/PacketReadingTestUtil.kt
index 964e0f15f..f5ea2d8c9 100644
--- a/src/integration-test/kotlin/de/bixilon/minosoft/protocol/packets/s2c/play/PacketReadingTestUtil.kt
+++ b/src/integration-test/kotlin/de/bixilon/minosoft/protocol/packets/s2c/play/PacketReadingTestUtil.kt
@@ -17,11 +17,12 @@ import de.bixilon.minosoft.protocol.network.connection.play.ConnectionTestUtil
 import de.bixilon.minosoft.protocol.network.connection.play.PlayConnection
 import de.bixilon.minosoft.protocol.packets.s2c.S2CPacket
 import de.bixilon.minosoft.protocol.protocol.buffers.play.PlayInByteBuffer
+import java.io.FileNotFoundException
 
 object PacketReadingTestUtil {
 
     fun <T : S2CPacket> read(name: String, version: String, connection: PlayConnection = ConnectionTestUtil.createConnection(version = version), constructor: (PlayInByteBuffer) -> T): T {
-        val data = PacketReadingTestUtil::class.java.getResourceAsStream("/packets/$name.bin")!!.readAllBytes()
+        val data = PacketReadingTestUtil::class.java.getResourceAsStream("/packets/$name.bin")?.readAllBytes() ?: throw FileNotFoundException("Can not find packet blob $name")
 
         val buffer = PlayInByteBuffer(data, connection)
 
diff --git a/src/integration-test/resources/packets/initialize/hypixel_1_19_4.bin b/src/integration-test/resources/packets/initialize/hypixel_1_19_4.bin
new file mode 100644
index 000000000..6297121e2
Binary files /dev/null and b/src/integration-test/resources/packets/initialize/hypixel_1_19_4.bin differ
diff --git a/src/integration-test/resources/packets/initialize/vanilla_1_15_2.bin b/src/integration-test/resources/packets/initialize/vanilla_1_15_2.bin
new file mode 100644
index 000000000..8997e6d8b
Binary files /dev/null and b/src/integration-test/resources/packets/initialize/vanilla_1_15_2.bin differ
diff --git a/src/integration-test/resources/packets/initialize/vanilla_1_16_5.bin b/src/integration-test/resources/packets/initialize/vanilla_1_16_5.bin
new file mode 100644
index 000000000..3572432ef
Binary files /dev/null and b/src/integration-test/resources/packets/initialize/vanilla_1_16_5.bin differ
diff --git a/src/integration-test/resources/packets/initialize/vanilla_1_20_1.bin b/src/integration-test/resources/packets/initialize/vanilla_1_20_1.bin
new file mode 100644
index 000000000..7590d548f
Binary files /dev/null and b/src/integration-test/resources/packets/initialize/vanilla_1_20_1.bin differ