diff --git a/runtime/openjdkjvmti/OpenjdkJvmTi.cc b/runtime/openjdkjvmti/OpenjdkJvmTi.cc
index d3561c1..a1a2361 100644
--- a/runtime/openjdkjvmti/OpenjdkJvmTi.cc
+++ b/runtime/openjdkjvmti/OpenjdkJvmTi.cc
@@ -29,15 +29,17 @@
  * questions.
  */
 
+#include <string>
+#include <vector>
+
 #include <jni.h>
+
 #include "openjdkjvmti/jvmti.h"
 
 #include "art_jvmti.h"
-#include "gc_root-inl.h"
-#include "globals.h"
 #include "jni_env_ext-inl.h"
-#include "scoped_thread_state_change.h"
-#include "thread_list.h"
+#include "runtime.h"
+#include "transform.h"
 
 // TODO Remove this at some point by annotating all the methods. It was put in to make the skeleton
 // easier to create.
@@ -904,6 +906,66 @@
   static jvmtiError GetJLocationFormat(jvmtiEnv* env, jvmtiJlocationFormat* format_ptr) {
     return ERR(NOT_IMPLEMENTED);
   }
+
+  // TODO Remove this once events are working.
+  static jvmtiError RetransformClassWithHook(jvmtiEnv* env,
+                                             jclass klass,
+                                             jvmtiEventClassFileLoadHook hook) {
+    std::vector<jclass> classes;
+    classes.push_back(klass);
+    return RetransformClassesWithHook(reinterpret_cast<ArtJvmTiEnv*>(env), classes, hook);
+  }
+
+  // TODO This will be called by the event handler for the art::ti Event Load Event
+  static jvmtiError RetransformClassesWithHook(ArtJvmTiEnv* env,
+                                               const std::vector<jclass>& classes,
+                                               jvmtiEventClassFileLoadHook hook) {
+    if (!IsValidEnv(env)) {
+      return ERR(INVALID_ENVIRONMENT);
+    }
+    for (jclass klass : classes) {
+      JNIEnv* jni_env = nullptr;
+      jobject loader = nullptr;
+      std::string name;
+      jobject protection_domain = nullptr;
+      jint data_len = 0;
+      unsigned char* dex_data = nullptr;
+      jvmtiError ret = OK;
+      std::string location;
+      if ((ret = GetTransformationData(env,
+                                       klass,
+                                       /*out*/&location,
+                                       /*out*/&jni_env,
+                                       /*out*/&loader,
+                                       /*out*/&name,
+                                       /*out*/&protection_domain,
+                                       /*out*/&data_len,
+                                       /*out*/&dex_data)) != OK) {
+        // TODO Do something more here? Maybe give log statements?
+        return ret;
+      }
+      jint new_data_len = 0;
+      unsigned char* new_dex_data = nullptr;
+      hook(env,
+           jni_env,
+           klass,
+           loader,
+           name.c_str(),
+           protection_domain,
+           data_len,
+           dex_data,
+           /*out*/&new_data_len,
+           /*out*/&new_dex_data);
+      // Check if anything actually changed.
+      if ((new_data_len != 0 || new_dex_data != nullptr) && new_dex_data != dex_data) {
+        MoveTransformedFileIntoRuntime(klass, std::move(location), new_data_len, new_dex_data);
+        env->Deallocate(new_dex_data);
+      }
+      // Deallocate the old dex data.
+      env->Deallocate(dex_data);
+    }
+    return OK;
+  }
 };
 
 static bool IsJvmtiVersion(jint version) {
@@ -942,7 +1004,10 @@
 
 // The actual struct holding all of the entrypoints into the jvmti interface.
 const jvmtiInterface_1 gJvmtiInterface = {
-  nullptr,  // reserved1
+  // SPECIAL FUNCTION: RetransformClassWithHook Is normally reserved1
+  // TODO Remove once we have events working.
+  reinterpret_cast<void*>(JvmtiFunctions::RetransformClassWithHook),
+  // nullptr,  // reserved1
   JvmtiFunctions::SetEventNotificationMode,
   nullptr,  // reserved3
   JvmtiFunctions::GetAllThreads,