diff --git a/CHANGELOG.md b/CHANGELOG.md
index ae47a39..4239b7d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 1.2.0
+
+- Backport to 1.20.1
+
 # 1.1.2
 - Fix YACL bindings incorrectly using the current value as the default
 
diff --git a/build.gradle.kts b/build.gradle.kts
index 1fa7a1c..e37e316 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -48,7 +48,7 @@ loom {
 
 tasks {
     withType<JavaCompile> {
-        options.release = 21
+        options.release = minecraftVersion.javaVersion()
     }
 
     withType<RemapJarTask> {
@@ -84,8 +84,8 @@ tasks {
 java {
     withSourcesJar()
 
-    sourceCompatibility = JavaVersion.VERSION_21
-    targetCompatibility = JavaVersion.VERSION_21
+    sourceCompatibility = JavaVersion.toVersion(minecraftVersion.javaVersion())
+    targetCompatibility = JavaVersion.toVersion(minecraftVersion.javaVersion())
 }
 
 val buildAndCollect = tasks.register<Copy>("buildAndCollect") {
diff --git a/gradle.properties b/gradle.properties
index 6be1461..341b7ae 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,15 +1,13 @@
 org.gradle.jvmargs=-Xmx4G
 
-fabric_versions=1.21.1
+fabric_versions=1.20.1, 1.21.1
 neoforge_versions=1.21.1
 
-mod_version=1.1.2
+mod_version=1.2.0
 mod_group=com.bawnorton
 mod_id=configurable
 mod_name=Configurable
 mod_description=Config library that allows decentralised settings in a mod
 
 modrinth_project_id=lGffrQ3O
-curseforge_project_id=1092048
-
-yacl_version=3.5.0+1.21
\ No newline at end of file
+curseforge_project_id=1092048
\ No newline at end of file
diff --git a/src/main/java/com/bawnorton/configurable/ap/ConfigurableProcessor.java b/src/main/java/com/bawnorton/configurable/ap/ConfigurableProcessor.java
index 38c5297..a72336c 100644
--- a/src/main/java/com/bawnorton/configurable/ap/ConfigurableProcessor.java
+++ b/src/main/java/com/bawnorton/configurable/ap/ConfigurableProcessor.java
@@ -25,6 +25,7 @@
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.util.Elements;
 import javax.lang.model.util.Types;
+import javax.tools.Diagnostic;
 import javax.tools.FileObject;
 import javax.tools.StandardLocation;
 import org.jetbrains.annotations.NotNull;
@@ -38,7 +39,11 @@
 import java.util.Set;
 
 @SupportedAnnotationTypes("com.bawnorton.configurable.Configurable")
-@SupportedSourceVersion(SourceVersion.RELEASE_21)
+//? if >=1.21 {
+/*@SupportedSourceVersion(SourceVersion.RELEASE_21)
+*///?} else {
+@SupportedSourceVersion(SourceVersion.RELEASE_17)
+//?}
 public final class ConfigurableProcessor extends AbstractProcessor {
     private final Gson gson = new GsonBuilder()
             .setFieldNamingStrategy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
@@ -88,19 +93,19 @@ public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment
                 sourceSet = null;
             }
         } catch (IOException e) {
-            messager.printError("Cannot determine source set");
+            messager.printMessage(Diagnostic.Kind.ERROR, "Cannot determine source set");
             throw new RuntimeException(e);
         }
 
         SourceProvider sourceProvider = SourceProviders.getSourceProvider(filer, buildPath);
         if(sourceProvider == null) {
-            messager.printError("Cannot determine source provider");
+            messager.printMessage(Diagnostic.Kind.ERROR,"Cannot determine source provider");
             throw new RuntimeException();
         }
 
         String configName = sourceProvider.getName();
         ConfigurableSettings settings = generateSettings(sourceSet, configName, buildPath);
-        messager.printNote("Found config name: \"%s\" for source set \"%s\"".formatted(settings.name(), settings.sourceSet()));
+        messager.printMessage(Diagnostic.Kind.NOTE, "Found config name: \"%s\" for source set \"%s\"".formatted(settings.name(), settings.sourceSet()));
 
         ConfigLoaderGenerator loaderGenerator = new ConfigLoaderGenerator(filer, types, messager, settings);
         ConfigGenerator configGenerator = new ConfigGenerator(filer, types, messager, settings);
@@ -115,7 +120,7 @@ public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment
                 screenFactoryGenerator.generateYaclScreenFactory(roots, configGenerator::getExternalReference);
             }
         } catch (IOException e) {
-            messager.printError("Could not generate config classes");
+            messager.printMessage(Diagnostic.Kind.ERROR,"Could not generate config classes");
             throw new RuntimeException(e);
         }
 
@@ -166,7 +171,7 @@ private void generateSettingsFile(ConfigurableSettings settings, Path buildPath)
                 out.write(gson.toJson(settings).getBytes());
             }
         } catch (IOException e) {
-            messager.printError("Could not write settings file");
+            messager.printMessage(Diagnostic.Kind.ERROR,"Could not write settings file");
             throw new RuntimeException(e);
         }
     }
diff --git a/src/main/java/com/bawnorton/configurable/ap/generator/ConfigGenerator.java b/src/main/java/com/bawnorton/configurable/ap/generator/ConfigGenerator.java
index 938fcc9..e79e74d 100644
--- a/src/main/java/com/bawnorton/configurable/ap/generator/ConfigGenerator.java
+++ b/src/main/java/com/bawnorton/configurable/ap/generator/ConfigGenerator.java
@@ -7,6 +7,7 @@
 import javax.annotation.processing.Messager;
 import javax.lang.model.element.Element;
 import javax.lang.model.util.Types;
+import javax.tools.Diagnostic;
 import javax.tools.JavaFileObject;
 import java.io.IOException;
 import java.io.PrintWriter;
@@ -147,7 +148,7 @@ private void addClampedConstraint(ConfigurableHolder holder, Element element, St
             double min = holder.min();
             double max = holder.max();
             if (min > max) {
-                messager.printError("min must be smaller than or equal to the max", element);
+                messager.printMessage(Diagnostic.Kind.ERROR, "min must be smaller than or equal to the max", element);
             }
             constraintSet.append(".addClamped(%s, %s)".formatted(min, max));
         }
diff --git a/src/main/java/com/bawnorton/configurable/ap/generator/ConfigLoaderGenerator.java b/src/main/java/com/bawnorton/configurable/ap/generator/ConfigLoaderGenerator.java
index 79446ae..2ef7686 100644
--- a/src/main/java/com/bawnorton/configurable/ap/generator/ConfigLoaderGenerator.java
+++ b/src/main/java/com/bawnorton/configurable/ap/generator/ConfigLoaderGenerator.java
@@ -96,9 +96,9 @@ private void parseNested(List<String> stack, JsonObject nestedJson, Config confi
        for(String key : keys) {
            JsonElement element = nestedJson.get(key);
            if(element.isJsonObject()) {
-               stack.addLast(key);
+               stack.add(key);
                parseNested(stack, element.getAsJsonObject(), config);
-               stack.removeLast();
+               stack.remove(stack.size() - 1);
            } else if (element.isJsonNull()) {
                parseReference(key, null, stack, config);
            } else if (element.isJsonPrimitive()) {
diff --git a/src/main/java/com/bawnorton/configurable/ap/generator/ConfigScreenFactoryGenerator.java b/src/main/java/com/bawnorton/configurable/ap/generator/ConfigScreenFactoryGenerator.java
index 30786a0..353b762 100644
--- a/src/main/java/com/bawnorton/configurable/ap/generator/ConfigScreenFactoryGenerator.java
+++ b/src/main/java/com/bawnorton/configurable/ap/generator/ConfigScreenFactoryGenerator.java
@@ -16,6 +16,7 @@
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.util.Elements;
 import javax.lang.model.util.Types;
+import javax.tools.Diagnostic;
 import javax.tools.JavaFileObject;
 import org.jetbrains.annotations.NotNull;
 import java.io.IOException;
@@ -257,7 +258,7 @@ private YaclRoot createYaclImpl(List<ConfigurableElement> roots, Function<Config
                             yield new YaclOptionController.Item();
                         }
                     }
-                    messager.printError("Could not automatically create controller for type: %s".formatted(entry.getFullyQualifiedTypeName(types)), entry.element());
+                    messager.printMessage(Diagnostic.Kind.ERROR, "Could not automatically create controller for type: %s".formatted(entry.getFullyQualifiedTypeName(types)), entry.element());
                     throw new RuntimeException();
                 }
                 case ARRAY -> new YaclOptionController.CyclingList(
@@ -265,7 +266,7 @@ private YaclRoot createYaclImpl(List<ConfigurableElement> roots, Function<Config
                         externalRef
                 );
                 default -> {
-                    messager.printError("Could not automatically create controller for type: %s".formatted(entry.getFullyQualifiedTypeName(types)), entry.element());
+                    messager.printMessage(Diagnostic.Kind.ERROR, "Could not automatically create controller for type: %s".formatted(entry.getFullyQualifiedTypeName(types)), entry.element());
                     throw new RuntimeException();
                 }
             };
diff --git a/src/main/java/com/bawnorton/configurable/ap/tree/ConfigurableTree.java b/src/main/java/com/bawnorton/configurable/ap/tree/ConfigurableTree.java
index 032de77..d740b8f 100644
--- a/src/main/java/com/bawnorton/configurable/ap/tree/ConfigurableTree.java
+++ b/src/main/java/com/bawnorton/configurable/ap/tree/ConfigurableTree.java
@@ -6,6 +6,7 @@
 import javax.lang.model.element.Element;
 import javax.lang.model.element.Modifier;
 import javax.lang.model.type.TypeKind;
+import javax.tools.Diagnostic;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.HashSet;
@@ -98,25 +99,25 @@ private ConfigurableElement createConfigurableElement(Element element) {
                 getAnnotationMirror(element, Configurable.class.getCanonicalName())
         );
         if (annotation == null) {
-            messager.printError("Element \"%s\" does not have Configurable annotation".formatted(element.getSimpleName()), element);
+            messager.printMessage(Diagnostic.Kind.ERROR, "Element \"%s\" does not have Configurable annotation".formatted(element.getSimpleName()), element);
             throw new RuntimeException();
         }
 
         Set<Modifier> modifiers = element.getModifiers();
         if(element.getKind().isField()) {
             if(modifiers.contains(Modifier.FINAL)) {
-                messager.printError("Configurable field \"%s\" cannot be final".formatted(element.getSimpleName()), element);
+                messager.printMessage(Diagnostic.Kind.ERROR, "Configurable field \"%s\" cannot be final".formatted(element.getSimpleName()), element);
                 throw new RuntimeException();
             } else if (!modifiers.contains(Modifier.STATIC)) {
-                messager.printError("Configurable field \"%s\" must be static".formatted(element.getSimpleName()), element);
+                messager.printMessage(Diagnostic.Kind.ERROR, "Configurable field \"%s\" must be static".formatted(element.getSimpleName()), element);
                 throw new RuntimeException();
             } else if(annotation.yacl().collapsed()) {
-                messager.printError("Configurable field \"%s\" cannot be collapsed, only classes allowed".formatted(element.getSimpleName()), element);
+                messager.printMessage(Diagnostic.Kind.ERROR, "Configurable field \"%s\" cannot be collapsed, only classes allowed".formatted(element.getSimpleName()), element);
                 throw new RuntimeException();
             }
         } else if (element.getKind().isClass()) {
             if(modifiers.contains(Modifier.PRIVATE)) {
-                messager.printError("Configurable class \"%s\" cannot be private".formatted(element.getSimpleName()), element);
+                messager.printMessage(Diagnostic.Kind.ERROR, "Configurable class \"%s\" cannot be private".formatted(element.getSimpleName()), element);
                 throw new RuntimeException();
             }
         }
@@ -129,7 +130,7 @@ private ConfigurableElement createConfigurableElement(Element element) {
                 .toList();
 
         if (element.getKind().isClass() && children.isEmpty()) {
-            messager.printError("Configurable class \"%s\" must have at least one Configurable field or class".formatted(element.getSimpleName()), element);
+            messager.printMessage(Diagnostic.Kind.ERROR, "Configurable class \"%s\" must have at least one Configurable field or class".formatted(element.getSimpleName()), element);
             throw new RuntimeException();
         }
 
@@ -144,7 +145,7 @@ private ConfigurableElement createConfigurableElement(Element element) {
                             .equals("org.spongepowered.asm.mixin.Mixin"))
                     .findFirst()
                     .ifPresent(mirror -> {
-                        messager.printError("Configurable element \"%s\" must be outside a mixin class".formatted(element.getSimpleName()), element);
+                        messager.printMessage(Diagnostic.Kind.ERROR, "Configurable element \"%s\" must be outside a mixin class".formatted(element.getSimpleName()), element);
                         throw new RuntimeException();
                     });
         }
diff --git a/src/main/java/com/bawnorton/configurable/ap/yacl/YaclDescriptionImage.java b/src/main/java/com/bawnorton/configurable/ap/yacl/YaclDescriptionImage.java
index ac3819e..529924e 100644
--- a/src/main/java/com/bawnorton/configurable/ap/yacl/YaclDescriptionImage.java
+++ b/src/main/java/com/bawnorton/configurable/ap/yacl/YaclDescriptionImage.java
@@ -30,20 +30,25 @@ protected String getSpec(int depth) {
         if(customOwner != null && customMethod != null) {
             return "customImage(%s)".formatted(getCustomImageSpec());
         }
+        //? if >=1.21 {
+        /*String id = "Identifier.of(\"%s\")".formatted(image.value());
+        *///?} else {
+        String id = "new Identifier(\"%s\")".formatted(image.value());
+        //?}
         return switch (image.type()) {
             case RESOURCE -> {
                 if(!image.path().isEmpty()) {
-                    yield "image(Path.of(\"%s\"), Identifier.of(\"%s\"))".formatted(
+                    yield "image(Path.of(\"%s\"), %s)".formatted(
                             image.path(),
-                            image.value()
+                            id
                     );
                 }
 
                 int textureWidth = image.textureWidth() == 0 ? image.width() : image.textureWidth();
                 int textureHeight = image.textureHeight() == 0 ? image.height() : image.textureHeight();
 
-                yield "image(Identifier.of(\"%s\"), %sF, %sF, %s, %s, %s, %s)".formatted(
-                        image.value(),
+                yield "image(%s, %sF, %sF, %s, %s, %s, %s)".formatted(
+                        id,
                         image.u(),
                         image.v(),
                         image.width(),
@@ -54,13 +59,13 @@ protected String getSpec(int depth) {
             }
             case WEBP -> {
                 if(!image.path().isEmpty()) {
-                    yield "webpImage(Path.of(\"%s\"), Identifier.of(\"%s\"))".formatted(
+                    yield "webpImage(Path.of(\"%s\"), %s)".formatted(
                             image.path(),
-                            image.value()
+                            id
                     );
                 }
 
-                yield "webpImage(Identifier.of(\"%s\"))".formatted(image.value());
+                yield "webpImage(%s)".formatted(id);
             }
         };
     }
diff --git a/src/main/java/com/bawnorton/configurable/client/mixin/ModMenuMixin.java b/src/main/java/com/bawnorton/configurable/client/mixin/ModMenuMixin.java
index 269c877..46a0390 100644
--- a/src/main/java/com/bawnorton/configurable/client/mixin/ModMenuMixin.java
+++ b/src/main/java/com/bawnorton/configurable/client/mixin/ModMenuMixin.java
@@ -20,9 +20,16 @@
 
 @Mixin(value = ModMenu.class, remap = false)
 public abstract class ModMenuMixin {
-    @Shadow @Final private static Map<String, ConfigScreenFactory<?>> configScreenFactories;
+    //? if >=1.21 {
+    /*@Shadow @Final private static Map<String, ConfigScreenFactory<?>> configScreenFactories;
 
     @Shadow @Final private static List<ModMenuApi> apiImplementations;
+    *///?} else {
+    @Shadow private static Map<String, ConfigScreenFactory<?>> configScreenFactories;
+
+    @Shadow private static List<Map<String, ConfigScreenFactory<?>>> delayedScreenFactoryProviders;
+    //?}
+
 
     @Inject(
             method = "onInitializeClient",
@@ -49,7 +56,11 @@ public ConfigScreenFactory<?> getModConfigScreenFactory() {
 
             ModMenuApi api = apiGetter.apply(wrapper);
             configScreenFactories.put(name, api.getModConfigScreenFactory());
-            apiImplementations.add(api);
+            //? if >=1.21 {
+            /*apiImplementations.add(api);
+            *///?} else {
+            delayedScreenFactoryProviders.add(api.getProvidedConfigScreenFactories());
+            //?}
         }));
     }
 }
diff --git a/src/main/java/com/bawnorton/configurable/ref/gson/ItemTypeAdapter.java b/src/main/java/com/bawnorton/configurable/ref/gson/ItemTypeAdapter.java
index 9463cce..5c024cd 100644
--- a/src/main/java/com/bawnorton/configurable/ref/gson/ItemTypeAdapter.java
+++ b/src/main/java/com/bawnorton/configurable/ref/gson/ItemTypeAdapter.java
@@ -19,7 +19,12 @@ public class ItemTypeAdapter implements JsonSerializer<Item>, JsonDeserializer<I
     public Item deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
         try {
             String itemName = json.getAsString();
-            return Registries.ITEM.getOrEmpty(Identifier.of(itemName)).orElse(Items.AIR);
+            //? if <1.21 {
+            Identifier id = new Identifier(itemName);
+            //?} else {
+            /*Identifier id = Identifier.of(itemName);
+            *///?}
+            return Registries.ITEM.getOrEmpty(id).orElse(Items.AIR);
         } catch (Exception e) {
             ConfigurableMain.LOGGER.warn("Failed to parse item from json: \"%s\"".formatted(json));
             return Items.AIR;
@@ -30,4 +35,4 @@ public Item deserialize(JsonElement json, Type typeOfT, JsonDeserializationConte
     public JsonElement serialize(Item src, Type typeOfSrc, JsonSerializationContext context) {
         return new JsonPrimitive(Registries.ITEM.getId(src).toString());
     }
-}
+}
\ No newline at end of file
diff --git a/src/main/resources/fabric.mod.json b/src/main/resources/fabric.mod.json
index 13fc9e1..dfc3f4a 100644
--- a/src/main/resources/fabric.mod.json
+++ b/src/main/resources/fabric.mod.json
@@ -33,7 +33,6 @@
   "depends": {
     "fabricloader": ">=0.15.0",
     "minecraft": "${minecraft_dependency}",
-    "java": ">=21",
     "fabric-api": "*"
   },
   "custom": {
diff --git a/stonecutter.gradle.kts b/stonecutter.gradle.kts
index 584861a..17a8686 100644
--- a/stonecutter.gradle.kts
+++ b/stonecutter.gradle.kts
@@ -1,7 +1,7 @@
 plugins {
     id("dev.kikugie.stonecutter")
 }
-stonecutter active "1.21.1-fabric-yarn" /* [SC] DO NOT EDIT */
+stonecutter active "1.20.1-fabric-yarn" /* [SC] DO NOT EDIT */
 
 stonecutter registerChiseled tasks.register("chiseledBuildAndCollect", stonecutter.chiseled) {
     group = "project"
diff --git a/versions/1.20.1-fabric-mojmap/gradle.properties b/versions/1.20.1-fabric-mojmap/gradle.properties
new file mode 100644
index 0000000..ef4df20
--- /dev/null
+++ b/versions/1.20.1-fabric-mojmap/gradle.properties
@@ -0,0 +1,10 @@
+loom.platform=fabric
+mappings=mojmap
+
+yarn_build=10
+fabric_loader=0.16.2
+minecraft_dependency=>=1.20.1
+supported_versions=1.20.1
+
+modmenu=7.2.2
+yacl_version=3.5.0+1.20.1
\ No newline at end of file
diff --git a/versions/1.20.1-fabric-yarn/gradle.properties b/versions/1.20.1-fabric-yarn/gradle.properties
new file mode 100644
index 0000000..4548d7a
--- /dev/null
+++ b/versions/1.20.1-fabric-yarn/gradle.properties
@@ -0,0 +1,10 @@
+loom.platform=fabric
+mappings=yarn
+
+yarn_build=10
+fabric_loader=0.16.2
+minecraft_dependency=>=1.20.1
+supported_versions=1.20.1
+
+modmenu=7.2.2
+yacl_version=3.5.0+1.20.1
\ No newline at end of file
diff --git a/versions/1.21.1-fabric-mojmap/gradle.properties b/versions/1.21.1-fabric-mojmap/gradle.properties
index ab2387e..7f2223f 100644
--- a/versions/1.21.1-fabric-mojmap/gradle.properties
+++ b/versions/1.21.1-fabric-mojmap/gradle.properties
@@ -6,4 +6,5 @@ fabric_loader=0.16.2
 minecraft_dependency=>=1.21
 supported_versions=1.21, 1.21.1
 
-modmenu=11.0.2
\ No newline at end of file
+modmenu=11.0.2
+yacl_version=3.5.0+1.21
\ No newline at end of file
diff --git a/versions/1.21.1-fabric-yarn/gradle.properties b/versions/1.21.1-fabric-yarn/gradle.properties
index 6ce9ab1..9a4a4f7 100644
--- a/versions/1.21.1-fabric-yarn/gradle.properties
+++ b/versions/1.21.1-fabric-yarn/gradle.properties
@@ -6,4 +6,5 @@ fabric_loader=0.16.2
 minecraft_dependency=>=1.21
 supported_versions=1.21, 1.21.1
 
-modmenu=11.0.2
\ No newline at end of file
+modmenu=11.0.2
+yacl_version=3.5.0+1.21
\ No newline at end of file
diff --git a/versions/1.21.1-neoforge-mojmap/gradle.properties b/versions/1.21.1-neoforge-mojmap/gradle.properties
index 0812b47..e3f5b40 100644
--- a/versions/1.21.1-neoforge-mojmap/gradle.properties
+++ b/versions/1.21.1-neoforge-mojmap/gradle.properties
@@ -4,4 +4,6 @@ mappings=mojmap
 yarn_build=3
 neoforge_loader=21.1.31
 minecraft_dependency=>=1.21
-supported_versions=1.21, 1.21.1
\ No newline at end of file
+supported_versions=1.21, 1.21.1
+
+yacl_version=3.5.0+1.21
\ No newline at end of file
diff --git a/versions/1.21.1-neoforge-yarn/gradle.properties b/versions/1.21.1-neoforge-yarn/gradle.properties
index d520214..eb14a7d 100644
--- a/versions/1.21.1-neoforge-yarn/gradle.properties
+++ b/versions/1.21.1-neoforge-yarn/gradle.properties
@@ -4,4 +4,6 @@ mappings=yarn
 yarn_build=3
 neoforge_loader=21.1.31
 minecraft_dependency=>=1.21
-supported_versions=1.21, 1.21.1
\ No newline at end of file
+supported_versions=1.21, 1.21.1
+
+yacl_version=3.5.0+1.21
\ No newline at end of file