diff --git a/core/java/android/os/IMountService.aidl b/core/java/android/os/IMountService.aidl
index e73569adc97ee..c0c2d036bb7db 100644
--- a/core/java/android/os/IMountService.aidl
+++ b/core/java/android/os/IMountService.aidl
@@ -93,6 +93,11 @@ interface IMountService
      */
     String mountSecureContainer(String id, String key, int ownerUid);
 
+    /*
+     * Unount a secure container.
+     */
+    void unmountSecureContainer(String id);
+
     /*
      * Returns the filesystem path of a mounted secure container.
      */
diff --git a/media/sdutils/sdutil.cpp b/media/sdutils/sdutil.cpp
index a30e59c037b35..322f743a36977 100644
--- a/media/sdutils/sdutil.cpp
+++ b/media/sdutils/sdutil.cpp
@@ -129,6 +129,11 @@ static int asec_mount(const char *id, const char *key, int ownerUid) {
     return 0;
 }
 
+static void asec_unmount(const char *id) {
+    String16 sId(id);
+    gMountService->unmountSecureContainer(sId);
+}
+
 static int asec_path(const char *id) {
     String16 sId(id);
     gMountService->getSecureContainerPath(sId);
@@ -208,6 +213,9 @@ int main(int argc, char **argv)
             return android::asec_destroy(id);
         } else if (!strcmp(argument, "mount")) {
             return android::asec_mount(id, argv[4], atoi(argv[5]));
+        } else if (!strcmp(argument, "unmount")) {
+            android::asec_unmount(id);
+            return 0;
         } else if (!strcmp(argument, "path")) {
             return android::asec_path(id);
         }
@@ -224,6 +232,7 @@ usage:
                     "    sdutil asec finalize <id>\n"
                     "    sdutil asec destroy <id>\n"
                     "    sdutil asec mount <id> <key> <ownerUid>\n"
+                    "    sdutil asec unmount <id>\n"
                     "    sdutil asec path <id>\n"
                     );
     return -1;
diff --git a/services/java/com/android/server/MountService.java b/services/java/com/android/server/MountService.java
index d54c4d904f9d3..f8f8742bb5cfa 100644
--- a/services/java/com/android/server/MountService.java
+++ b/services/java/com/android/server/MountService.java
@@ -1057,6 +1057,11 @@ class MountService extends IMountService.Stub
         return getSecureContainerPath(id);
     }
 
+    public void unmountSecureContainer(String id) throws IllegalStateException {
+        String cmd = String.format("unmount_asec %s ", id);
+        mConnector.doCommand(cmd);
+    }
+
     public String getSecureContainerPath(String id) throws IllegalStateException {
         ArrayList<String> rsp = mConnector.doCommand("asec_path " + id);