diff --git a/api/shadow.api b/api/shadow.api
index e9bb98b26..bbee96bb6 100644
--- a/api/shadow.api
+++ b/api/shadow.api
@@ -434,6 +434,15 @@ public class com/github/jengelman/gradle/plugins/shadow/transformers/DontInclude
 }
 
 public class com/github/jengelman/gradle/plugins/shadow/transformers/GroovyExtensionModuleTransformer : com/github/jengelman/gradle/plugins/shadow/transformers/Transformer {
+	public static final field Companion Lcom/github/jengelman/gradle/plugins/shadow/transformers/GroovyExtensionModuleTransformer$Companion;
+	public static final field EXTENSION_CLASSES_KEY Ljava/lang/String;
+	public static final field GROOVY_EXTENSION_MODULE_DESCRIPTOR_PATH Ljava/lang/String;
+	public static final field GROOVY_LEGACY_EXTENSION_MODULE_DESCRIPTOR_PATH Ljava/lang/String;
+	public static final field MERGED_MODULE_NAME Ljava/lang/String;
+	public static final field MERGED_MODULE_VERSION Ljava/lang/String;
+	public static final field MODULE_NAME_KEY Ljava/lang/String;
+	public static final field MODULE_VERSION_KEY Ljava/lang/String;
+	public static final field STATIC_EXTENSION_CLASSES_KEY Ljava/lang/String;
 	public fun <init> ()V
 	public fun canTransformResource (Lorg/gradle/api/file/FileTreeElement;)Z
 	public fun hasTransformedResource ()Z
@@ -441,6 +450,9 @@ public class com/github/jengelman/gradle/plugins/shadow/transformers/GroovyExten
 	public fun transform (Lcom/github/jengelman/gradle/plugins/shadow/transformers/TransformerContext;)V
 }
 
+public final class com/github/jengelman/gradle/plugins/shadow/transformers/GroovyExtensionModuleTransformer$Companion {
+}
+
 public class com/github/jengelman/gradle/plugins/shadow/transformers/IncludeResourceTransformer : com/github/jengelman/gradle/plugins/shadow/transformers/Transformer {
 	public fun <init> (Lorg/gradle/api/model/ObjectFactory;)V
 	public fun canTransformResource (Lorg/gradle/api/file/FileTreeElement;)Z
diff --git a/src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/transformers/GroovyExtensionModuleTransformer.kt b/src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/transformers/GroovyExtensionModuleTransformer.kt
index d0884e210..3cfba5754 100644
--- a/src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/transformers/GroovyExtensionModuleTransformer.kt
+++ b/src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/transformers/GroovyExtensionModuleTransformer.kt
@@ -1,9 +1,7 @@
 package com.github.jengelman.gradle.plugins.shadow.transformers
 
+import com.github.jengelman.gradle.plugins.shadow.internal.inputStream
 import com.github.jengelman.gradle.plugins.shadow.transformers.TransformerContext.Companion.getEntryTimestamp
-import java.io.ByteArrayInputStream
-import java.io.ByteArrayOutputStream
-import java.io.InputStream
 import java.util.Properties
 import org.apache.tools.zip.ZipEntry
 import org.apache.tools.zip.ZipOutputStream
@@ -88,22 +86,16 @@ public open class GroovyExtensionModuleTransformer : Transformer {
     os.closeEntry()
   }
 
-  private companion object {
-    private fun Properties.inputStream(): InputStream {
-      val os = ByteArrayOutputStream()
-      store(os, null)
-      return ByteArrayInputStream(os.toByteArray())
-    }
-
-    private const val GROOVY_LEGACY_EXTENSION_MODULE_DESCRIPTOR_PATH =
+  public companion object {
+    public const val GROOVY_LEGACY_EXTENSION_MODULE_DESCRIPTOR_PATH: String =
       "META-INF/services/org.codehaus.groovy.runtime.ExtensionModule"
-    private const val GROOVY_EXTENSION_MODULE_DESCRIPTOR_PATH =
+    public const val GROOVY_EXTENSION_MODULE_DESCRIPTOR_PATH: String =
       "META-INF/groovy/org.codehaus.groovy.runtime.ExtensionModule"
-    private const val MODULE_NAME_KEY = "moduleName"
-    private const val MODULE_VERSION_KEY = "moduleVersion"
-    private const val EXTENSION_CLASSES_KEY = "extensionClasses"
-    private const val STATIC_EXTENSION_CLASSES_KEY = "staticExtensionClasses"
-    private const val MERGED_MODULE_NAME = "MergedByShadowJar"
-    private const val MERGED_MODULE_VERSION = "1.0.0"
+    public const val MODULE_NAME_KEY: String = "moduleName"
+    public const val MODULE_VERSION_KEY: String = "moduleVersion"
+    public const val EXTENSION_CLASSES_KEY: String = "extensionClasses"
+    public const val STATIC_EXTENSION_CLASSES_KEY: String = "staticExtensionClasses"
+    public const val MERGED_MODULE_NAME: String = "MergedByShadowJar"
+    public const val MERGED_MODULE_VERSION: String = "1.0.0"
   }
 }