diff --git a/src/main/java/net/fabricmc/loom/LoomGradleExtension.java b/src/main/java/net/fabricmc/loom/LoomGradleExtension.java
index d9fe4b8e..d1686574 100644
--- a/src/main/java/net/fabricmc/loom/LoomGradleExtension.java
+++ b/src/main/java/net/fabricmc/loom/LoomGradleExtension.java
@@ -57,6 +57,7 @@ import net.fabricmc.loom.configuration.providers.minecraft.mapped.NamedMinecraft
 import net.fabricmc.loom.configuration.providers.minecraft.mapped.SrgMinecraftProvider;
 import net.fabricmc.loom.extension.LoomFiles;
 import net.fabricmc.loom.extension.MixinExtension;
+import net.fabricmc.loom.util.ModPlatform;
 
 public interface LoomGradleExtension extends LoomGradleExtensionAPI {
 	static LoomGradleExtension get(Project project) {
@@ -117,7 +118,10 @@ public interface LoomGradleExtension extends LoomGradleExtensionAPI {
 		case NAMED -> getNamedMinecraftProvider().getMinecraftJars();
 		case INTERMEDIARY -> getIntermediaryMinecraftProvider().getMinecraftJars();
 		case OFFICIAL -> getMinecraftProvider().getMinecraftJars();
-		case SRG -> getSrgMinecraftProvider().getMinecraftJars();
+		case SRG -> {
+			ModPlatform.assertPlatform(this, ModPlatform.FORGE, () -> "SRG jars are only available on Forge.");
+			yield getSrgMinecraftProvider().getMinecraftJars();
+		}
 		};
 	}
 
diff --git a/src/main/java/net/fabricmc/loom/task/MigrateMappingsTask.java b/src/main/java/net/fabricmc/loom/task/MigrateMappingsTask.java
index 1866a83e..53cb545a 100644
--- a/src/main/java/net/fabricmc/loom/task/MigrateMappingsTask.java
+++ b/src/main/java/net/fabricmc/loom/task/MigrateMappingsTask.java
@@ -181,8 +181,10 @@ public class MigrateMappingsTask extends AbstractLoomTask {
 			mercury.getClassPath().add(intermediaryJar);
 		}
 
-		for (Path srgJar : extension.getMinecraftJars(MappingsNamespace.SRG)) {
-			mercury.getClassPath().add(srgJar);
+		if (extension.isForge()) {
+			for (Path srgJar : extension.getMinecraftJars(MappingsNamespace.SRG)) {
+				mercury.getClassPath().add(srgJar);
+			}
 		}
 
 		mercury.getProcessors().add(MercuryRemapper.create(mappingSet));
diff --git a/src/main/java/net/fabricmc/loom/util/ModPlatform.java b/src/main/java/net/fabricmc/loom/util/ModPlatform.java
index 0f7ce897..d1112d09 100644
--- a/src/main/java/net/fabricmc/loom/util/ModPlatform.java
+++ b/src/main/java/net/fabricmc/loom/util/ModPlatform.java
@@ -1,7 +1,7 @@
 /*
  * This file is part of fabric-loom, licensed under the MIT License (MIT).
  *
- * Copyright (c) 2021 FabricMC
+ * Copyright (c) 2021-2022 FabricMC
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -25,6 +25,7 @@
 package net.fabricmc.loom.util;
 
 import java.util.Locale;
+import java.util.function.Supplier;
 
 import org.gradle.api.GradleException;
 import org.gradle.api.Project;
@@ -41,10 +42,16 @@ public enum ModPlatform {
 	}
 
 	public static void assertPlatform(LoomGradleExtensionAPI extension, ModPlatform platform) {
-		if (extension.getPlatform().get() != platform) {
+		assertPlatform(extension, platform, () -> {
 			String msg = "Loom is not running on %s.%nYou can switch to it by adding 'loom.platform = %s' to your gradle.properties";
 			String name = platform.name().toLowerCase(Locale.ROOT);
-			throw new GradleException(String.format(msg, name, name));
+			return msg.formatted(name, name);
+		});
+	}
+
+	public static void assertPlatform(LoomGradleExtensionAPI extension, ModPlatform platform, Supplier<String> message) {
+		if (extension.getPlatform().get() != platform) {
+			throw new GradleException(message.get());
 		}
 	}
 }