diff --git a/MagickCore/segment.c b/MagickCore/segment.c
index 1af1734..a592854 100644
--- a/MagickCore/segment.c
+++ b/MagickCore/segment.c
@@ -1833,6 +1833,7 @@
   /*
     Initialize histogram.
   */
+  SyncImagePixelCache(image,exception);
   InitializeHistogram(image,histogram,exception);
   (void) OptimalTau(histogram[Red],Tau,0.2,DeltaTau,
     smooth_threshold == 0.0 ? 1.0 : smooth_threshold,extrema[Red]);