diff --git a/libs/gui/IGraphicBufferConsumer.cpp b/libs/gui/IGraphicBufferConsumer.cpp
index 1b19626..ab644de 100644
--- a/libs/gui/IGraphicBufferConsumer.cpp
+++ b/libs/gui/IGraphicBufferConsumer.cpp
@@ -298,14 +298,18 @@
         return reply.readInt32();
     }
 
-    virtual status_t getReleasedBuffers(uint32_t* slotMask) {
+    virtual status_t getReleasedBuffers(uint64_t* slotMask) {
         Parcel data, reply;
+        if (slotMask == NULL) {
+            ALOGE("getReleasedBuffers: slotMask must not be NULL");
+            return BAD_VALUE;
+        }
         data.writeInterfaceToken(IGraphicBufferConsumer::getInterfaceDescriptor());
         status_t result = remote()->transact(GET_RELEASED_BUFFERS, data, &reply);
         if (result != NO_ERROR) {
             return result;
         }
-        *slotMask = reply.readInt32();
+        *slotMask = reply.readInt64();
         return reply.readInt32();
     }
 
@@ -480,9 +484,9 @@
         } break;
         case GET_RELEASED_BUFFERS: {
             CHECK_INTERFACE(IGraphicBufferConsumer, data, reply);
-            uint32_t slotMask;
+            uint64_t slotMask;
             status_t result = getReleasedBuffers(&slotMask);
-            reply->writeInt32(slotMask);
+            reply->writeInt64(slotMask);
             reply->writeInt32(result);
             return NO_ERROR;
         } break;