diff --git a/MagickCore/thread-private.h b/MagickCore/thread-private.h
index dbe3848..7a109d4 100644
--- a/MagickCore/thread-private.h
+++ b/MagickCore/thread-private.h
@@ -34,7 +34,8 @@
if (((((columns) > WorkloadThreshold()) || \
((rows) > WorkloadThreshold()))) && ((MagickSizeType) \
((columns)*(rows)) > (WorkloadThreshold()*WorkloadThreshold())) && \
- (IsPixelCacheInCore(image) != MagickFalse) && (expression)) \
+ ((GetImagePixelCacheType(image) == MemoryCache) || \
+ (GetImagePixelCacheType(image) == MapCache)) && (expression)) \
num_threads(GetMagickResourceLimit(ThreadResource))
#if (__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR > 10))