diff --git a/src/search.cpp b/src/search.cpp
index 54990ce6f03..cbd454efb76 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1053,9 +1053,11 @@ Value Search::Worker::search(
                     int doubleMargin = 298 * PvNode - 209 * !ttCapture;
                     int tripleMargin =
                       117 + 252 * PvNode - 270 * !ttCapture + 111 * (ss->ttPv || !ttCapture);
+                    int quadMargin = 471 + 343 * PvNode - 281 * !ttCapture + 217 * ss->ttPv;
 
                     extension = 1 + (value < singularBeta - doubleMargin)
-                              + (value < singularBeta - tripleMargin);
+                              + (value < singularBeta - tripleMargin)
+                              + (value < singularBeta - quadMargin);
 
                     depth += ((!PvNode) && (depth < 15));
                 }