diff --git a/src/main/java/net/fabricmc/loom/util/Constants.java b/src/main/java/net/fabricmc/loom/util/Constants.java
index 5adcecd6..8d6d0018 100644
--- a/src/main/java/net/fabricmc/loom/util/Constants.java
+++ b/src/main/java/net/fabricmc/loom/util/Constants.java
@@ -65,8 +65,8 @@ public class Constants {
 
 	public static final IDelayed<File> VERSION_MANIFEST = new DelayedFile(extension -> new File(extension.getUserCache(), "version_manifest.json"));
 
-	public static final String FABRIC_CLIENT_TWEAKER = "net.fabricmc.base.launch.FabricClientTweaker";
-	public static final String FABRIC_SERVER_TWEAKER = "net.fabricmc.base.launch.FabricServerTweaker";
+	public static final String FABRIC_CLIENT_TWEAKER = "net.fabricmc.loader.launch.FabricClientTweaker";
+	public static final String FABRIC_SERVER_TWEAKER = "net.fabricmc.loader.launch.FabricServerTweaker";
 	public static final String POMF_JENKINS_SERVER = "http://modmuss50.me:8080";
 
 	public static final String LIBRARIES_BASE = "https://libraries.minecraft.net/";