diff --git a/OT/BaseOT.cpp b/OT/BaseOT.cpp
index be5e2ad87..24ed5af23 100644
--- a/OT/BaseOT.cpp
+++ b/OT/BaseOT.cpp
@@ -246,6 +246,10 @@ void BaseOT::exec_base(bool new_receiver_inputs)
         #endif
     }
 
+    if (ot_role & SENDER)
+        for (int i = 0; i < nOT; i++)
+            assert(sender_inputs.at(i).at(0) != sender_inputs.at(i).at(1));
+
     // Hash with counter to avoid collisions
     for (int i = 0; i < nOT; i++)
     {
@@ -256,8 +260,16 @@ void BaseOT::exec_base(bool new_receiver_inputs)
                 hash_with_id(sender_inputs.at(i).at(j), i);
     }
 
+    if (ot_role & SENDER)
+        for (int i = 0; i < nOT; i++)
+            assert(sender_inputs.at(i).at(0) != sender_inputs.at(i).at(1));
+
     // Set PRG seeds
     set_seeds();
+
+    if (ot_role & SENDER)
+        for (int i = 0; i < nOT; i++)
+            assert(sender_inputs.at(i).at(0) != sender_inputs.at(i).at(1));
 }
 
 void BaseOT::hash_with_id(BitVector& bits, long id)
diff --git a/Tools/BitVector.h b/Tools/BitVector.h
index 89c404996..06965417d 100644
--- a/Tools/BitVector.h
+++ b/Tools/BitVector.h
@@ -242,6 +242,11 @@ class BitVector
         return equals(other);
     }
 
+    bool operator!=(const BitVector& other) const
+    {
+        return not equals(other);
+    }
+
     void append(const BitVector& other, size_t length);
 
     void randomize(PRNG& G);