diff --git a/README.md b/README.md
index 2f195b9d..a6b3be53 100644
--- a/README.md
+++ b/README.md
@@ -53,13 +53,6 @@ material from being accidentally included in the repository.
 Run `./gradlew` to download the dependencies, build the code, run the unit tests
 and package it.
 
-IDEA 2020.3's built-in build system breaks with a cryptic
-`java: java.lang.IllegalArgumentException` error message when compiling modules
-that use the `deob-annotations` processor. A workaround is to add
-`-Djps.track.ap.dependencies=false` to the 'Shared build process VM options' in
-File -> Settings -> Build, Execution and Deployment -> Compiler. See
-[IDEA-256707][idea-bug] for more information.
-
 ## Links
 
 * [Discord][discord]
diff --git a/deob-processor/src/main/kotlin/org/openrs2/deob/processor/NameMapProcessor.kt b/deob-processor/src/main/kotlin/org/openrs2/deob/processor/NameMapProcessor.kt
index f53ec6e7..8630ef4e 100644
--- a/deob-processor/src/main/kotlin/org/openrs2/deob/processor/NameMapProcessor.kt
+++ b/deob-processor/src/main/kotlin/org/openrs2/deob/processor/NameMapProcessor.kt
@@ -14,6 +14,7 @@ import org.openrs2.deob.util.map.Method
 import org.openrs2.deob.util.map.NameMap
 import org.openrs2.util.io.useAtomicBufferedWriter
 import org.openrs2.yaml.Yaml
+import java.lang.reflect.Proxy
 import java.nio.file.Files
 import java.nio.file.Path
 import java.util.TreeMap
@@ -51,10 +52,22 @@ public class NameMapProcessor : AbstractProcessor() {
 
     override fun init(env: ProcessingEnvironment) {
         super.init(env)
-        trees = Trees.instance(env)
+        trees = Trees.instance(unwrap(env))
         localScanner = LocalVariableScanner(trees)
     }
 
+    // see https://youtrack.jetbrains.com/issue/IDEA-256707
+    private fun unwrap(env: ProcessingEnvironment): ProcessingEnvironment {
+        if (!Proxy.isProxyClass(env.javaClass)) {
+            return env
+        }
+
+        val invocationHandler = Proxy.getInvocationHandler(env)
+        val field = invocationHandler.javaClass.getDeclaredField("val\$delegateTo")
+        field.isAccessible = true
+        return field.get(invocationHandler) as ProcessingEnvironment
+    }
+
     private fun getPath(): Path? {
         val map = processingEnv.options["map"] ?: return null
         return Path.of(map)