diff --git a/src/material.cpp b/src/material.cpp
index 71e057a7..5e8f75d9 100644
--- a/src/material.cpp
+++ b/src/material.cpp
@@ -146,6 +146,7 @@ MaterialInfoTable::MaterialInfoTable() {
            << " bytes for material hash table." << endl;
       Application::exit_with_failure();
   }
+  memset(entries, 0, MaterialTableSize * sizeof(MaterialInfo));
 }
 
 MaterialInfoTable::~MaterialInfoTable() {
diff --git a/src/pawns.cpp b/src/pawns.cpp
index 07decab1..9a0059dc 100644
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -90,6 +90,7 @@ PawnInfoTable::PawnInfoTable() {
                 << " bytes for pawn hash table." << std::endl;
       Application::exit_with_failure();
   }
+  memset(entries, 0, PawnTableSize * sizeof(PawnInfo));
 }
 
 
diff --git a/src/tt.cpp b/src/tt.cpp
index b730dbeb..375c00a6 100644
--- a/src/tt.cpp
+++ b/src/tt.cpp
@@ -72,6 +72,7 @@ void TranspositionTable::set_size(size_t mbSize) {
                     << " MB for transposition table." << std::endl;
           Application::exit_with_failure();
       }
+      clear();
   }
 }