diff --git a/RecoPixelVertexing/PixelTriplets/plugins/CAConstants.h b/RecoPixelVertexing/PixelTriplets/plugins/CAConstants.h
index 8ea536465814c..8d651479060c5 100644
--- a/RecoPixelVertexing/PixelTriplets/plugins/CAConstants.h
+++ b/RecoPixelVertexing/PixelTriplets/plugins/CAConstants.h
@@ -32,9 +32,10 @@ namespace caConstants {
   constexpr uint32_t maxCellsPerHit = 128 / 2;
 #else   // GPU_SMALL_EVENTS
   // tested on MC events with 55-75 pileup events
-  constexpr uint32_t maxNumberOfTuples = 24 * 1024;
+  // and extended for Heavy Ions operations (24k -> 32k tuples, 128 -> 256 cells)
+  constexpr uint32_t maxNumberOfTuples = 32 * 1024;
   constexpr uint32_t maxNumberOfDoublets = 512 * 1024;
-  constexpr uint32_t maxCellsPerHit = 128;
+  constexpr uint32_t maxCellsPerHit = 256;
 #endif  // GPU_SMALL_EVENTS
 #endif  // ONLY_PHICUT
   constexpr uint32_t maxNumOfActiveDoublets = maxNumberOfDoublets / 8;