arm_compute v18.11
diff --git a/tests/validation/reference/EqualizeHistogram.cpp b/tests/validation/reference/EqualizeHistogram.cpp
index 0e966cd..1a10c2c 100644
--- a/tests/validation/reference/EqualizeHistogram.cpp
+++ b/tests/validation/reference/EqualizeHistogram.cpp
@@ -66,7 +66,7 @@
     }
     else
     {
-        const float diff = total_num_pixels - 1;
+        const float diff = total_num_pixels - cd_min;
 
         for(size_t i = 0; i < num_bins; ++i)
         {