diff --git a/services/camera/libcameraservice/api1/client2/CallbackProcessor.cpp b/services/camera/libcameraservice/api1/client2/CallbackProcessor.cpp
index 5c8f750..88c5811 100644
--- a/services/camera/libcameraservice/api1/client2/CallbackProcessor.cpp
+++ b/services/camera/libcameraservice/api1/client2/CallbackProcessor.cpp
@@ -395,7 +395,7 @@
 
         heapIdx = mCallbackHeapHead;
 
-        mCallbackHeapHead = (mCallbackHeapHead + 1) & kCallbackHeapCount;
+        mCallbackHeapHead = (mCallbackHeapHead + 1) % kCallbackHeapCount;
         mCallbackHeapFree--;
 
         // TODO: Get rid of this copy by passing the gralloc queue all the way