diff --git a/exp-drd/drd_bitmap.c b/exp-drd/drd_bitmap.c
index 3ff24d7..26963ee 100644
--- a/exp-drd/drd_bitmap.c
+++ b/exp-drd/drd_bitmap.c
@@ -141,8 +141,6 @@
   struct bitmap2* bm2;
 
   bm2 = bm2_lookup_or_insert(bm, a1 >> ADDR0_BITS);
-  tl_assert(bm2);
-
   bm0_set_range(bm2->bm1.bm0_r, a1 & ADDR0_MASK, size);
 }
 
@@ -153,8 +151,6 @@
   struct bitmap2* bm2;
 
   bm2 = bm2_lookup_or_insert(bm, a1 >> ADDR0_BITS);
-  tl_assert(bm2);
-
   bm0_set_range(bm2->bm1.bm0_w, a1 & ADDR0_MASK, size);
 }
 
diff --git a/exp-drd/drd_bitmap.h b/exp-drd/drd_bitmap.h
index cd2244b..ecc71d5 100644
--- a/exp-drd/drd_bitmap.h
+++ b/exp-drd/drd_bitmap.h
@@ -40,7 +40,7 @@
 
 /* Macro definitions. */
 
-#define ADDR0_BITS 12
+#define ADDR0_BITS 16
 
 #define ADDR0_COUNT ((UWord)1 << ADDR0_BITS)
 
@@ -159,7 +159,6 @@
   const UWord a1 = a >> ADDR0_BITS;
   if (a1 == bm->last_lookup_a1)
   {
-    //tl_assert(bm->last_lookup_result == VG_(OSetGen_Lookup)(bm->oset, &a1));
     return bm->last_lookup_result;
   }
   result = VG_(OSetGen_Lookup)(bm->oset,&a1);
@@ -196,7 +195,6 @@
 
   if (a1 == bm->last_lookup_a1)
   {
-    //tl_assert(bm->last_lookup_result == VG_(OSetGen_Lookup)(bm->oset, &a1));
     return bm->last_lookup_result;
   }