diff --git a/services/core/java/com/android/server/pm/Installer.java b/services/core/java/com/android/server/pm/Installer.java
index c0f1eec19e251..718996011d8e5 100644
--- a/services/core/java/com/android/server/pm/Installer.java
+++ b/services/core/java/com/android/server/pm/Installer.java
@@ -27,6 +27,7 @@ import android.util.Slog;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.List;
 
 public final class Installer extends SystemService {
     private static final String TAG = "Installer";
@@ -345,8 +346,8 @@ public final class Installer extends SystemService {
         }
     }
 
-    public int pruneDexCache() {
-        return execute("prunedexcache");
+    public int pruneDexCache(String cacheSubDir) {
+        return execute("prunedexcache " + cacheSubDir);
     }
 
     public int freeCache(long freeStorageSize) {
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index 3736df4662acd..2f53504818489 100755
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -1443,9 +1443,6 @@ public class PackageManagerService extends IPackageManager.Stub {
                 // changed. Consider this significant, and wipe away all other
                 // existing dexopt files to ensure we don't leave any dangling around.
                 //
-                // Additionally, delete all dex files from the root directory
-                // since there shouldn't be any there anyway.
-                //
                 // TODO: This should be revisited because it isn't as good an indicator
                 // as it used to be. It used to include the boot classpath but at some point
                 // DexFile.isDexOptNeeded started returning false for the boot
@@ -1453,7 +1450,15 @@ public class PackageManagerService extends IPackageManager.Stub {
                 // small maintenance release update that the library and tool
                 // jars may be unchanged but APK could be removed resulting in
                 // unused dalvik-cache files.
-                mInstaller.pruneDexCache();
+                for (String instructionSet : instructionSets) {
+                    mInstaller.pruneDexCache(instructionSet);
+                }
+
+                // Additionally, delete all dex files from the root directory
+                // since there shouldn't be any there anyway, unless we're upgrading
+                // from an older OS version or a build that contained the "old" style
+                // flat scheme.
+                mInstaller.pruneDexCache(".");
             }
 
             // Collect vendor overlay packages.