diff --git a/src/main/java/net/fabricmc/loom/configuration/RemapConfiguration.java b/src/main/java/net/fabricmc/loom/configuration/RemapConfiguration.java
index cf6d1e9..03d19e3 100644
--- a/src/main/java/net/fabricmc/loom/configuration/RemapConfiguration.java
+++ b/src/main/java/net/fabricmc/loom/configuration/RemapConfiguration.java
@@ -107,9 +107,9 @@ public class RemapConfiguration {
 		assert remapJarTask != null;
 
 		if (!remapJarTask.getInput().isPresent() && isDefaultRemap) {
-			jarTask.setClassifier("dev");
-			remapJarTask.setClassifier("");
-			remapJarTask.getInput().set(jarTask.getArchivePath());
+			jarTask.getArchiveClassifier().convention("dev");
+			remapJarTask.getArchiveClassifier().convention("");
+			remapJarTask.getInput().convention(jarTask.getArchiveFile());
 		}
 
 		if (isDefaultRemap) {
@@ -177,8 +177,8 @@ public class RemapConfiguration {
 
 			RemapSourcesJarTask remapSourcesJarTask = (RemapSourcesJarTask) project.getTasks().findByName(remapSourcesJarTaskName);
 			Preconditions.checkNotNull(remapSourcesJarTask, "Could not find " + remapSourcesJarTaskName + " in " + project.getName());
-			remapSourcesJarTask.getInput().set(sourcesTask.getArchiveFile());
-			remapSourcesJarTask.getOutput().set(sourcesTask.getArchiveFile());
+			remapSourcesJarTask.getInput().convention(sourcesTask.getArchiveFile());
+			remapSourcesJarTask.getOutput().convention(sourcesTask.getArchiveFile());
 			remapSourcesJarTask.dependsOn(project.getTasks().getByName(sourcesJarTaskName));
 
 			if (isDefaultRemap) {