diff --git a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java
index 81f24a23..9f2a5d2e 100644
--- a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java
+++ b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java
@@ -38,6 +38,7 @@ import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.tasks.SourceSet;
 
 import net.fabricmc.loom.LoomGradleExtension;
+import net.fabricmc.loom.configuration.providers.minecraft.MinecraftSourceSets;
 import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.OperatingSystem;
 
@@ -103,7 +104,11 @@ public final class RunConfigSettings implements Named {
 		this.extension = LoomGradleExtension.get(project);
 		this.ideConfigGenerated = extension.isRootProject();
 
-		source("main");
+		setSource(p -> {
+			final String sourceSetName = MinecraftSourceSets.get(p).getSourceSetForEnv(getEnvironment());
+			return p.getExtensions().getByType(JavaPluginExtension.class).getSourceSets().getByName(sourceSetName);
+		});
+
 		runDir("run");
 	}
 
diff --git a/src/main/java/net/fabricmc/loom/task/LoomTasks.java b/src/main/java/net/fabricmc/loom/task/LoomTasks.java
index 5ce99e76..4bdbb39b 100644
--- a/src/main/java/net/fabricmc/loom/task/LoomTasks.java
+++ b/src/main/java/net/fabricmc/loom/task/LoomTasks.java
@@ -34,7 +34,6 @@ import org.gradle.api.tasks.TaskProvider;
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.configuration.ide.RunConfigSettings;
 import net.fabricmc.loom.configuration.providers.minecraft.MinecraftJarConfiguration;
-import net.fabricmc.loom.configuration.providers.minecraft.MinecraftSourceSets;
 import net.fabricmc.loom.task.launch.GenerateDLIConfigTask;
 import net.fabricmc.loom.task.launch.GenerateLog4jConfigTask;
 import net.fabricmc.loom.task.launch.GenerateRemapClasspathTask;
@@ -156,17 +155,6 @@ public final class LoomTasks {
 
 			extension.getRunConfigs().removeIf(settings -> settings.getName().equals(taskName));
 		});
-
-		// Configure the run config source sets.
-		project.afterEvaluate(p -> {
-			if (!extension.areEnvironmentSourceSetsSplit()) {
-				return;
-			}
-
-			extension.getRunConfigs().configureEach(settings ->
-					settings.source(MinecraftSourceSets.get(project).getSourceSetForEnv(settings.getEnvironment()))
-			);
-		});
 	}
 
 	public static Provider<Task> getIDELaunchConfigureTaskName(Project project) {