diff --git a/libs/gui/bufferqueue/1.0/Conversion.cpp b/libs/gui/bufferqueue/1.0/Conversion.cpp
index 3e20a37..55462c3 100644
--- a/libs/gui/bufferqueue/1.0/Conversion.cpp
+++ b/libs/gui/bufferqueue/1.0/Conversion.cpp
@@ -1187,14 +1187,15 @@
  */
 constexpr size_t minFlattenedSize(
         HGraphicBufferProducer::QueueBufferInput const& /* t */) {
-    return sizeof(int64_t) + // timestamp
-            sizeof(int) + // isAutoTimestamp
+    return sizeof(int64_t) +            // timestamp
+            sizeof(int) +               // isAutoTimestamp
             sizeof(android_dataspace) + // dataSpace
-            sizeof(::android::Rect) + // crop
-            sizeof(int) + // scalingMode
-            sizeof(uint32_t) + // transform
-            sizeof(uint32_t) + // stickyTransform
-            sizeof(bool); // getFrameTimestamps
+            sizeof(::android::Rect) +   // crop
+            sizeof(int) +               // scalingMode
+            sizeof(uint32_t) +          // transform
+            sizeof(uint32_t) +          // stickyTransform
+            sizeof(bool) +              // getFrameTimestamps
+            sizeof(int);                // slot
 }
 
 /**
@@ -1267,6 +1268,7 @@
         return status;
     }
     FlattenableUtils::write(buffer, size, decltype(HdrMetadata::validTypes)(0));
+    FlattenableUtils::write(buffer, size, -1 /*slot*/);
     return NO_ERROR;
 }
 
@@ -1319,7 +1321,7 @@
     if (status != NO_ERROR) {
         return status;
     }
-    // HdrMetadata ignored
+    // HdrMetadata and slot ignored
     return unflatten(&(t->surfaceDamage), buffer, size);
 }