diff --git a/src/dalvik_system_DexFile.cc b/src/dalvik_system_DexFile.cc
index bb486e2..6e0a923 100644
--- a/src/dalvik_system_DexFile.cc
+++ b/src/dalvik_system_DexFile.cc
@@ -19,9 +19,12 @@
 #include "class_loader.h"
 #include "class_linker.h"
 #include "dex_file.h"
+#include "file.h"
 #include "logging.h"
 #include "os.h"
 #include "runtime.h"
+#include "space.h"
+#include "zip_archive.h"
 #include "toStringArray.h"
 #include "ScopedUtfChars.h"
 
@@ -79,7 +82,7 @@
     void operator=(const NullableScopedUtfChars&);
 };
 
-static jint DexFile_openDexFile(JNIEnv* env, jclass, jstring javaSourceName, jstring javaOutputName) {
+static jint DexFile_openDexFile(JNIEnv* env, jclass, jstring javaSourceName, jstring javaOutputName, jint) {
   ScopedUtfChars sourceName(env, javaSourceName);
   if (sourceName.c_str() == NULL) {
     return 0;
@@ -89,14 +92,82 @@
     return 0;
   }
   if (outputName.c_str() != NULL) {
-    // TODO: extract dex and run dex2oat like oatopt
-    UNIMPLEMENTED(FATAL) << sourceName.c_str() << " " << outputName.c_str();
+    // Check that output name ends in .dex.
+    if (!StringPiece(outputName.c_str()).ends_with(".dex")) {
+      LOG(ERROR) << "Output filename '" << outputName.c_str() << "' does not end with .dex";
+      return 0;
+    }
+
+    // Extract the dex file.
+    UniquePtr<ZipArchive> zip_archive(ZipArchive::Open(sourceName.c_str()));
+    if (zip_archive.get() == NULL) {
+      LOG(ERROR) << "Failed to open " << sourceName.c_str() << " when looking for classes.dex";
+      return 0;
+    }
+
+    UniquePtr<ZipEntry> zip_entry(zip_archive->Find(DexFile::kClassesDex));
+    if (zip_entry.get() == NULL) {
+      LOG(ERROR) << "Failed to find classes.dex within " << sourceName.c_str();
+      return 0;
+    }
+
+    UniquePtr<File> file(OS::OpenFile(outputName.c_str(), true));
+    bool success = zip_entry->Extract(*file);
+    if (!success) {
+      LOG(ERROR) << "Failed to extract classes.dex from " << sourceName.c_str();
+      return 0;
+    }
+
+    // Fork and exec dex2oat.
+    pid_t pid = fork();
+    if (pid == 0) {
+      std::string boot_image_option("--boot-image=");
+      boot_image_option += Heap::GetSpaces()[0]->GetImageFilename();
+
+      std::string dex_file_option("--dex-file=");
+      dex_file_option += outputName.c_str();
+
+      std::string oat_file_option("--oat=");
+      oat_file_option += outputName.c_str();
+      oat_file_option.erase(oat_file_option.size() - 3);
+      oat_file_option += "oat";
+
+      execl("/system/bin/dex2oatd",
+            "/system/bin/dex2oatd",
+            "-Xms64m",
+            "-Xmx64m",
+            boot_image_option.c_str(),
+            dex_file_option.c_str(),
+            oat_file_option.c_str(),
+            NULL);
+
+      PLOG(FATAL) << "execl(dex2oatd) failed";
+      return 0;
+    } else {
+      // Wait for dex2oat to finish.
+      int status;
+      pid_t got_pid = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0));
+      if (got_pid != pid) {
+        PLOG(ERROR) << "waitpid failed: wanted " << pid << ", got " << got_pid;
+        return 0;
+      }
+      if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+        LOG(ERROR) << "dex2oatd failed with dex-file=" << outputName.c_str();
+        return 0;
+      }
+    }
   }
-  const DexFile* dex_file = DexFile::Open(sourceName.c_str(), "");
+
+  const DexFile* dex_file;
+  if (outputName.c_str() == NULL) {
+    dex_file = DexFile::Open(sourceName.c_str(), "");
+  } else {
+    dex_file = DexFile::Open(outputName.c_str(), "");
+  }
   if (dex_file == NULL) {
     jniThrowExceptionFmt(env, "java/io/IOException", "unable to open DEX file: %s",
                          sourceName.c_str());
-    return NULL;
+    return 0;
   }
   return static_cast<jint>(reinterpret_cast<uintptr_t>(dex_file));
 }
diff --git a/src/space.h b/src/space.h
index d312365..7ebc654 100644
--- a/src/space.h
+++ b/src/space.h
@@ -83,6 +83,11 @@
     return *image_header_;
   }
 
+  const std::string& GetImageFilename() const {
+    CHECK(IsImageSpace());
+    return name_;
+  }
+
   size_t AllocationSize(const Object* obj);
 
  private:
diff --git a/test/071-dexfile/src/Main.java b/test/071-dexfile/src/Main.java
index 2cbe380..0845e87 100644
--- a/test/071-dexfile/src/Main.java
+++ b/test/071-dexfile/src/Main.java
@@ -22,8 +22,8 @@
  * DexFile tests (Dalvik-specific).
  */
 public class Main {
-    private static final String CLASS_PATH = "test-ex.jar";
-    private static final String ODEX_DIR = "/sdcard";
+    private static final String CLASS_PATH = "/data/art-test/071-dexfile-ex.jar";
+    private static final String ODEX_DIR = "/data/art-test";
     //private static final String ODEX_DIR = ".";
     private static final String ODEX_ALT = "/tmp";
     private static final String LIB_DIR = "/nowhere/nothing/";
diff --git a/test/etc/default-build b/test/etc/default-build
index 0ac7fbf..9647794 100755
--- a/test/etc/default-build
+++ b/test/etc/default-build
@@ -46,10 +46,4 @@
     zip ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME-ex.jar classes.dex
     mv classes.dex classes-ex.dex
     mv classes-1.dex classes.dex
-
-    dex2oatd -Xms16m -Xmx16m \
-        --boot-image=${ANDROID_PRODUCT_OUT}/data/art-test/core.art \
-        --dex-file=${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME-ex.jar \
-        --oat=${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME-ex.oat \
-        --host-prefix=${ANDROID_PRODUCT_OUT}
 fi
diff --git a/test/etc/push-and-run-test-jar b/test/etc/push-and-run-test-jar
index 24bc8c6..bcc0ceb 100755
--- a/test/etc/push-and-run-test-jar
+++ b/test/etc/push-and-run-test-jar
@@ -85,15 +85,11 @@
   adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME.oat /data/art-test
   adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME.art /data/art-test
   adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME-ex.jar /data/art-test
-  adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME-ex.oat /data/art-test
-  adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME-ex.art /data/art-test
 else
   adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME.jar /data/art-test >/dev/null 2>&1
   adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME.oat /data/art-test >/dev/null 2>&1
   adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME.art /data/art-test >/dev/null 2>&1
   adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME-ex.jar /data/art-test >/dev/null 2>&1
-  adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME-ex.oat /data/art-test >/dev/null 2>&1
-  adb push ${ANDROID_PRODUCT_OUT}/data/art-test/$TEST_NAME-ex.art /data/art-test >/dev/null 2>&1
 fi
 
 if [ "$DEBUG" = "y" ]; then