diff --git a/libs/binder/BpBinder.cpp b/libs/binder/BpBinder.cpp
index 50c7053..238c9dc 100644
--- a/libs/binder/BpBinder.cpp
+++ b/libs/binder/BpBinder.cpp
@@ -214,16 +214,21 @@
 {
     // Once a binder has died, it will never come back to life.
     if (mAlive) {
+        bool privateVendor = flags & FLAG_PRIVATE_VENDOR;
+        // don't send userspace flags to the kernel
+        flags = flags & ~FLAG_PRIVATE_VENDOR;
+
         // user transactions require a given stability level
         if (code >= FIRST_CALL_TRANSACTION && code <= LAST_CALL_TRANSACTION) {
             using android::internal::Stability;
 
             auto stability = Stability::get(this);
+            auto required = privateVendor ? Stability::VENDOR : Stability::kLocalStability;
 
-            if (CC_UNLIKELY(!Stability::check(stability, Stability::kLocalStability))) {
+            if (CC_UNLIKELY(!Stability::check(stability, required))) {
                 ALOGE("Cannot do a user transaction on a %s binder in a %s context.",
                     Stability::stabilityString(stability).c_str(),
-                    Stability::stabilityString(Stability::kLocalStability).c_str());
+                    Stability::stabilityString(required).c_str());
                 return BAD_TYPE;
             }
         }
diff --git a/libs/binder/include/binder/IBinder.h b/libs/binder/include/binder/IBinder.h
index 64f3052..64604b7 100644
--- a/libs/binder/include/binder/IBinder.h
+++ b/libs/binder/include/binder/IBinder.h
@@ -62,7 +62,11 @@
         DEBUG_PID_TRANSACTION   = B_PACK_CHARS('_', 'P', 'I', 'D'),
 
         // Corresponds to TF_ONE_WAY -- an asynchronous call.
-        FLAG_ONEWAY             = 0x00000001
+        FLAG_ONEWAY             = 0x00000001,
+
+        // Private userspace flag for transaction which is being requested from
+        // a vendor context.
+        FLAG_PRIVATE_VENDOR     = 0x10000000,
     };
 
                           IBinder();
diff --git a/libs/binder/ndk/ibinder.cpp b/libs/binder/ndk/ibinder.cpp
index b06ca86..e752c45 100644
--- a/libs/binder/ndk/ibinder.cpp
+++ b/libs/binder/ndk/ibinder.cpp
@@ -17,6 +17,7 @@
 #include <android/binder_ibinder.h>
 #include "ibinder_internal.h"
 
+#include <android/binder_stability.h>
 #include <android/binder_status.h>
 #include "parcel_internal.h"
 #include "status_internal.h"
@@ -542,7 +543,8 @@
         return STATUS_UNKNOWN_TRANSACTION;
     }
 
-    if ((flags & ~FLAG_ONEWAY) != 0) {
+    constexpr binder_flags_t kAllFlags = FLAG_PRIVATE_VENDOR | FLAG_ONEWAY;
+    if ((flags & ~kAllFlags) != 0) {
         LOG(ERROR) << __func__ << ": Unrecognized flags sent: " << flags;
         return STATUS_BAD_VALUE;
     }
diff --git a/libs/binder/ndk/include_platform/android/binder_stability.h b/libs/binder/ndk/include_platform/android/binder_stability.h
index 924812e..2a4ded8 100644
--- a/libs/binder/ndk/include_platform/android/binder_stability.h
+++ b/libs/binder/ndk/include_platform/android/binder_stability.h
@@ -20,9 +20,23 @@
 
 __BEGIN_DECLS
 
+/**
+ * Private addition to binder_flag_t.
+ */
+enum {
+    /**
+     * Indicates that this transaction is coupled w/ vendor.img
+     */
+    FLAG_PRIVATE_VENDOR = 0x10000000,
+};
+
 #if defined(__ANDROID_APEX_COM_ANDROID_VNDK_CURRENT__) || \
         (defined(__ANDROID_VNDK__) && !defined(__ANDROID_APEX__))
 
+enum {
+    FLAG_PRIVATE_LOCAL = FLAG_PRIVATE_VENDOR,
+};
+
 /**
  * This interface has the stability of the vendor image.
  */
@@ -35,6 +49,10 @@
 #else  // defined(__ANDROID_APEX_COM_ANDROID_VNDK_CURRENT__) || (defined(__ANDROID_VNDK__) &&
        // !defined(__ANDROID_APEX__))
 
+enum {
+    FLAG_PRIVATE_LOCAL = 0,
+};
+
 /**
  * This interface has the stability of the system image.
  */