diff --git a/mps/code/amssshe.c b/mps/code/amssshe.c
index a042a06d3ed..d80a83f7aaa 100644
--- a/mps/code/amssshe.c
+++ b/mps/code/amssshe.c
@@ -28,7 +28,8 @@
 #define totalSizeMAX    800 * (size_t)1024
 #define totalSizeSTEP   200 * (size_t)1024
 /* objNULL needs to be odd so that it's ignored in exactRoots. */
-#define objNULL         ((mps_addr_t)0xDECEA5ED)
+/* @@@@ Temporary fix for W3I6MV build ull */
+#define objNULL         ((mps_addr_t)0xDECEA5EDull)
 #define testArenaSIZE   ((size_t)16<<20)
 #define initTestFREQ    6000
 static mps_gen_param_s testChain[1] = { { 160, 0.90 } };
@@ -89,7 +90,11 @@ static void *test(void *arg, size_t s)
   for(i = 0; i < exactRootsCOUNT; ++i)
     exactRoots[i] = objNULL;
   for(i = 0; i < ambigRootsCOUNT; ++i)
+/* @@@@ Temporary fix W3I6MV */
+#pragma warning( push )
+#pragma warning( disable : 4306 )
     ambigRoots[i] = (mps_addr_t)rnd();
+#pragma warning( pop )
 
   die(mps_root_create_table_masked(&exactRoot, arena,
                                    MPS_RANK_EXACT, (mps_rm_t)0,
diff --git a/mps/code/mpsicv.c b/mps/code/mpsicv.c
index f2d3aa6f2da..0d4fcf88361 100644
--- a/mps/code/mpsicv.c
+++ b/mps/code/mpsicv.c
@@ -29,7 +29,8 @@
 #define patternFREQ      100
 
 /* objNULL needs to be odd so that it's ignored in exactRoots. */
-#define objNULL         ((mps_addr_t)0xDECEA5ED)
+/* @@@@ Temporary fix W3I6MV ull */
+#define objNULL         ((mps_addr_t)0xDECEA5EDull)
 #define FILLER_OBJECT_SIZE 1023
 
 #define genCOUNT          2
@@ -261,9 +262,11 @@ static void addr_pool_test(mps_arena_t arena,
   mps_bool_t b;
   mps_addr_t addr;
   /* DISTInguished values are to observe overwrites. */
-  mps_pool_t poolDistinguished = (mps_pool_t)0x000d1521;
+  /* @@@@ Temporary fix W3I6MV ull */
+  mps_pool_t poolDistinguished = (mps_pool_t)0x000d1521ull;
   mps_pool_t pool = poolDistinguished;
-  mps_fmt_t fmtDistinguished = (mps_fmt_t)0x000d1521;
+  /* @@@@ Temporary fix W3I6MV ull */
+  mps_fmt_t fmtDistinguished = (mps_fmt_t)0x000d1521ull;
   mps_fmt_t fmt = fmtDistinguished;
 
   /* 0a -- obj1 in pool1 (unformatted) */
@@ -427,13 +430,18 @@ static void *test(void *arg, size_t s)
     exactRoots[j] = objNULL;
   }
   for(j = 0; j < ambigRootsCOUNT; ++j) {
+/* @@@@ Temporary fix W3I6MV */
+#pragma warning( push )
+#pragma warning( disable : 4306 )
     ambigRoots[j] = (mps_addr_t)rnd();
+#pragma warning( pop )
   }
 
+/* @@@@ Temporary fix W3I6MV ull */
   die(mps_root_create_table_masked(&exactRoot, arena,
                                    MPS_RANK_EXACT, (mps_rm_t)0,
                                    &exactRoots[0], exactRootsCOUNT,
-                                   (mps_word_t)1),
+                                   (mps_word_t)1ull),
       "root_create_table(exact)");
   die(mps_root_create_table(&ambigRoot, arena,
                             MPS_RANK_AMBIG, (mps_rm_t)0,
@@ -474,7 +482,7 @@ static void *test(void *arg, size_t s)
   collections = mps_collections(arena);
 
   for(i = 0; i < OBJECTS; ++i) {
-    unsigned c;
+    mps_word_t c;
     size_t r;
 
     c = mps_collections(arena);
diff --git a/mps/code/segsmss.c b/mps/code/segsmss.c
index 71036b3edbb..c0b18af8f6f 100644
--- a/mps/code/segsmss.c
+++ b/mps/code/segsmss.c
@@ -714,7 +714,8 @@ static mps_class_t mps_class_amst(void)
 #define totalSizeMAX    sizeScale * 800 * (size_t)1024
 #define totalSizeSTEP   200 * (size_t)1024
 /* objNULL needs to be odd so that it's ignored in exactRoots. */
-#define objNULL         ((mps_addr_t)0xDECEA5ED)
+/* @@@@ Temporary fix W3I6MV */
+#define objNULL         ((mps_addr_t)0xDECEA5EDDECEA5ED)
 #define testArenaSIZE   ((size_t)16<<20)
 #define initTestFREQ    6000
 #define stressTestFREQ  40
@@ -778,7 +779,11 @@ static void *test(void *arg, size_t s)
   for(i = 0; i < exactRootsCOUNT; ++i)
     exactRoots[i] = objNULL;
   for(i = 0; i < ambigRootsCOUNT; ++i)
+/* @@@@ Temporary fix W3I6MV */
+#pragma warning( push )
+#pragma warning( disable : 4306 )
     ambigRoots[i] = (mps_addr_t)rnd();
+#pragma warning( pop )
 
   die(mps_root_create_table_masked(&exactRoot, arena,
                                    MPS_RANK_EXACT, (mps_rm_t)0,
diff --git a/mps/code/steptest.c b/mps/code/steptest.c
index 16477d10f8e..0f357c511ea 100644
--- a/mps/code/steptest.c
+++ b/mps/code/steptest.c
@@ -63,7 +63,8 @@ static int test_number = 0;
 
 
 /* objNULL needs to be odd so that it's ignored in exactRoots. */
-#define objNULL           ((mps_addr_t)0xDECEA5ED)
+/* @@@@ Temporary fix W3I6MV */
+#define objNULL           ((mps_addr_t)0xDECEA5EDull)
 
 static mps_pool_t pool;
 static mps_ap_t ap;
@@ -83,7 +84,7 @@ double total_clock_time; /* Time spent reading the clock */
 long clock_reads;        /* Number of times clock is read */
 long steps;              /* # of mps_arena_step calls returning 1 */
 long no_steps;           /* # of mps_arena_step calls returning 0 */
-long alloc_bytes;        /* # of bytes allocated */
+size_t alloc_bytes;      /* # of bytes allocated */
 long commit_failures;    /* # of times mps_commit fails */
 
 
@@ -323,7 +324,11 @@ static void *test(void *arg, size_t s)
     for(i = 0; i < exactRootsCOUNT; ++i)
         exactRoots[i] = objNULL;
     for(i = 0; i < ambigRootsCOUNT; ++i)
-        ambigRoots[i] = (mps_addr_t)rnd();
+/* @@@@ Temporary fix W3I6MV */
+#pragma warning( push )
+#pragma warning( disable : 4306 )
+    ambigRoots[i] = (mps_addr_t)rnd();
+#pragma warning( pop )
 
     die(mps_root_create_table_masked(&exactRoot, arena,
                                      MPS_RANK_EXACT, (mps_rm_t)0,