diff --git a/src/search.cpp b/src/search.cpp
index 04f73e1c..ec7cff54 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1067,7 +1067,10 @@ moves_loop: // When in check, search starts here
                   if (  !PvNode
                       && value < singularBeta - 25
                       && ss->doubleExtensions <= 9)
+                  {
                       extension = 2;
+                      depth += depth < 12;
+                  }
               }
 
               // Multi-cut pruning
@@ -1296,7 +1299,7 @@ moves_loop: // When in check, search starts here
                       && depth < 6
                       && beta  <  VALUE_KNOWN_WIN
                       && alpha > -VALUE_KNOWN_WIN)
-                     depth -= 1;
+                      depth -= 1;
 
                   assert(depth > 0);
               }
@@ -1521,7 +1524,6 @@ moves_loop: // When in check, search starts here
           &&  futilityBase > -VALUE_KNOWN_WIN
           &&  type_of(move) != PROMOTION)
       {
-
           if (moveCount > 2)
               continue;
 
diff --git a/src/types.h b/src/types.h
index c2087c6c..29c16ce7 100644
--- a/src/types.h
+++ b/src/types.h
@@ -186,6 +186,9 @@ enum Value : int {
   VALUE_MATE_IN_MAX_PLY  =  VALUE_MATE - MAX_PLY,
   VALUE_MATED_IN_MAX_PLY = -VALUE_MATE_IN_MAX_PLY,
 
+  // In the code, we make the assumption that these values
+  // are such that non_pawn_material() can be used to uniquely
+  // identify the material on the board.
   PawnValueMg   = 126,   PawnValueEg   = 208,
   KnightValueMg = 781,   KnightValueEg = 854,
   BishopValueMg = 825,   BishopValueEg = 915,