diff --git a/basis/compiler/cfg/value-numbering/value-numbering-tests.factor b/basis/compiler/cfg/value-numbering/value-numbering-tests.factor
index 55ff39e9d2..b404c4d4a4 100644
--- a/basis/compiler/cfg/value-numbering/value-numbering-tests.factor
+++ b/basis/compiler/cfg/value-numbering/value-numbering-tests.factor
@@ -82,7 +82,7 @@ IN: compiler.cfg.value-numbering.tests
         T{ ##load-reference f 1 + }
         T{ ##peek f 2 D 0 }
         T{ ##compare f 4 2 1 cc> }
-        T{ ##compare-imm f 6 4 5 cc/= }
+        T{ ##compare-imm f 6 4 $[ \ f type-number ] cc/= }
         T{ ##replace f 6 D 0 }
     } value-numbering-step trim-temps
 ] unit-test
@@ -100,7 +100,7 @@ IN: compiler.cfg.value-numbering.tests
         T{ ##load-reference f 1 + }
         T{ ##peek f 2 D 0 }
         T{ ##compare f 4 2 1 cc<= }
-        T{ ##compare-imm f 6 4 5 cc= }
+        T{ ##compare-imm f 6 4 $[ \ f type-number ] cc= }
         T{ ##replace f 6 D 0 }
     } value-numbering-step trim-temps
 ] unit-test
@@ -118,7 +118,7 @@ IN: compiler.cfg.value-numbering.tests
         T{ ##peek f 8 D 0 }
         T{ ##peek f 9 D -1 }
         T{ ##compare-float-unordered f 12 8 9 cc< }
-        T{ ##compare-imm f 14 12 5 cc= }
+        T{ ##compare-imm f 14 12 $[ \ f type-number ] cc= }
         T{ ##replace f 14 D 0 }
     } value-numbering-step trim-temps
 ] unit-test
@@ -135,7 +135,7 @@ IN: compiler.cfg.value-numbering.tests
         T{ ##peek f 29 D -1 }
         T{ ##peek f 30 D -2 }
         T{ ##compare f 33 29 30 cc<= }
-        T{ ##compare-imm-branch f 33 5 cc/= }
+        T{ ##compare-imm-branch f 33 $[ \ f type-number ] cc/= }
     } value-numbering-step trim-temps
 ] unit-test
 
@@ -149,7 +149,7 @@ IN: compiler.cfg.value-numbering.tests
     {
         T{ ##peek f 1 D -1 }
         T{ ##test-vector f 2 1 f float-4-rep vcc-any }
-        T{ ##compare-imm-branch f 2 5 cc/= }
+        T{ ##compare-imm-branch f 2 $[ \ f type-number ] cc/= }
     } value-numbering-step trim-temps
 ] unit-test
 
@@ -1071,14 +1071,14 @@ cell 8 = [
 ! Branch folding
 [
     {
-        T{ ##load-immediate f 1 1 }
-        T{ ##load-immediate f 2 2 }
-        T{ ##load-immediate f 3 5 }
+        T{ ##load-immediate f 1 10 }
+        T{ ##load-immediate f 2 20 }
+        T{ ##load-immediate f 3 $[ \ f type-number ] }
     }
 ] [
     {
-        T{ ##load-immediate f 1 1 }
-        T{ ##load-immediate f 2 2 }
+        T{ ##load-immediate f 1 10 }
+        T{ ##load-immediate f 2 20 }
         T{ ##compare f 3 1 2 cc= }
     } value-numbering-step
 ] unit-test
@@ -1113,14 +1113,14 @@ cell 8 = [
 
 [
     {
-        T{ ##load-immediate f 1 1 }
-        T{ ##load-immediate f 2 2 }
-        T{ ##load-immediate f 3 5 }
+        T{ ##load-immediate f 1 10 }
+        T{ ##load-immediate f 2 20 }
+        T{ ##load-immediate f 3 $[ \ f type-number ] }
     }
 ] [
     {
-        T{ ##load-immediate f 1 1 }
-        T{ ##load-immediate f 2 2 }
+        T{ ##load-immediate f 1 10 }
+        T{ ##load-immediate f 2 20 }
         T{ ##compare f 3 2 1 cc< }
     } value-numbering-step
 ] unit-test
@@ -1128,7 +1128,7 @@ cell 8 = [
 [
     {
         T{ ##peek f 0 D 0 }
-        T{ ##load-immediate f 1 5 }
+        T{ ##load-immediate f 1 $[ \ f type-number ] }
     }
 ] [
     {
@@ -1152,7 +1152,7 @@ cell 8 = [
 [
     {
         T{ ##peek f 0 D 0 }
-        T{ ##load-immediate f 1 5 }
+        T{ ##load-immediate f 1 $[ \ f type-number ] }
     }
 ] [
     {
@@ -1176,7 +1176,7 @@ cell 8 = [
 [
     {
         T{ ##peek f 0 D 0 }
-        T{ ##load-immediate f 1 5 }
+        T{ ##load-immediate f 1 $[ \ f type-number ] }
     }
 ] [
     {
@@ -1557,7 +1557,7 @@ cell 8 = [
     {
         T{ ##peek f 0 D 0 }
         T{ ##compare f 1 0 0 cc<= }
-        T{ ##compare-imm-branch f 1 5 cc/= }
+        T{ ##compare-imm-branch f 1 $[ \ f type-number ] cc/= }
     } test-branch-folding
 ] unit-test
 
@@ -1659,7 +1659,7 @@ V{
     T{ ##copy { dst 21 } { src 20 } { rep any-rep } }
     T{ ##compare-imm-branch
         { src1 21 }
-        { src2 5 }
+        { src2 $[ \ f type-number ] }
         { cc cc/= }
     }
 } 1 test-bb
diff --git a/basis/compiler/tests/intrinsics.factor b/basis/compiler/tests/intrinsics.factor
index dfc1af9a11..202ee57a33 100644
--- a/basis/compiler/tests/intrinsics.factor
+++ b/basis/compiler/tests/intrinsics.factor
@@ -285,8 +285,8 @@ cell 8 = [
 
 ! 64-bit overflow
 cell 8 = [
-    [ t ] [ 1 59 fixnum-shift dup [ fixnum+ ] compile-call 1 60 fixnum-shift = ] unit-test
-    [ -1152921504606846977 ] [ 1 60 shift neg >fixnum [ -1 fixnum+ ] compile-call ] unit-test
+    [ t ] [ 1 58 fixnum-shift dup [ fixnum+ ] compile-call 1 59 fixnum-shift = ] unit-test
+    [ -576460752303423489 ] [ 1 59 shift neg >fixnum [ -1 fixnum+ ] compile-call ] unit-test
     
     [ t ] [ 1 40 shift 1 40 shift [ fixnum* ] compile-call 1 80 shift = ] unit-test
     [ t ] [ 1 40 shift neg 1 40 shift [ fixnum* ] compile-call 1 80 shift neg = ] unit-test
@@ -301,9 +301,9 @@ cell 8 = [
     [ -18446744073709551616 ] [ -1 [ 64 fixnum-shift ] compile-call ] unit-test
     [ -18446744073709551616 ] [ -1 [ 32 fixnum-shift 32 fixnum-shift ] compile-call ] unit-test
     
-    [ 1152921504606846976 ] [ -1152921504606846976 >fixnum -1 [ fixnum/i ] compile-call ] unit-test
+    [ 576460752303423488 ] [ -576460752303423488 >fixnum -1 [ fixnum/i ] compile-call ] unit-test
 
-    [ 1152921504606846976 0 ] [ -1152921504606846976 >fixnum -1 [ fixnum/mod ] compile-call ] unit-test
+    [ 576460752303423488 0 ] [ -576460752303423488 >fixnum -1 [ fixnum/mod ] compile-call ] unit-test
 
     [ -268435457 ] [ 28 2^ [ fixnum-bitnot ] compile-call ] unit-test
 ] when
@@ -311,12 +311,14 @@ cell 8 = [
 ! Some randomized tests
 : compiled-fixnum* ( a b -- c ) fixnum* ;
 
+ERROR: bug-in-fixnum* x y a b ;
+
 [ ] [
     10000 [ 
-        32 random-bits >fixnum 32 random-bits >fixnum
-        2dup
-        [ fixnum* ] 2keep compiled-fixnum* =
-        [ 2drop ] [ "Oops" throw ] if
+        32 random-bits >fixnum
+        32 random-bits >fixnum
+        2dup [ fixnum* ] [ compiled-fixnum* ] 2bi 2dup =
+        [ 2drop 2drop ] [ bug-in-fixnum* ] if
     ] times
 ] unit-test
 
diff --git a/basis/compiler/tests/low-level-ir.factor b/basis/compiler/tests/low-level-ir.factor
index 583b228eb2..b6b8e1c031 100644
--- a/basis/compiler/tests/low-level-ir.factor
+++ b/basis/compiler/tests/low-level-ir.factor
@@ -36,7 +36,7 @@ IN: compiler.tests.low-level-ir
 ! loading immediates
 [ f ] [
     V{
-        T{ ##load-immediate f 0 5 }
+        T{ ##load-immediate f 0 $[ \ f type-number ] }
     } compile-test-bb
 ] unit-test
 
@@ -80,7 +80,7 @@ IN: compiler.tests.low-level-ir
     dup first eq?
 ] unit-test
 
-[ 8 ] [
+[ 4 ] [
     V{
         T{ ##load-immediate f 0 4 }
         T{ ##shl f 0 0 0 }
@@ -90,16 +90,16 @@ IN: compiler.tests.low-level-ir
 [ 4 ] [
     V{
         T{ ##load-immediate f 0 4 }
-        T{ ##shl-imm f 0 0 3 }
+        T{ ##shl-imm f 0 0 4 }
     } compile-test-bb
 ] unit-test
 
 [ 31 ] [
     V{
         T{ ##load-reference f 1 B{ 31 67 52 } }
-        T{ ##unbox-any-c-ptr f 0 1 2 }
+        T{ ##unbox-any-c-ptr f 0 1 }
         T{ ##alien-unsigned-1 f 0 0 0 }
-        T{ ##shl-imm f 0 0 3 }
+        T{ ##shl-imm f 0 0 4 }
     } compile-test-bb
 ] unit-test
 
@@ -108,13 +108,13 @@ IN: compiler.tests.low-level-ir
         T{ ##load-reference f 0 "hello world" }
         T{ ##load-immediate f 1 3 }
         T{ ##string-nth f 0 0 1 2 }
-        T{ ##shl-imm f 0 0 3 }
+        T{ ##shl-imm f 0 0 4 }
     } compile-test-bb
 ] unit-test
 
 [ 1 ] [
     V{
-        T{ ##load-immediate f 0 16 }
-        T{ ##add-imm f 0 0 -8 }
+        T{ ##load-immediate f 0 32 }
+        T{ ##add-imm f 0 0 -16 }
     } compile-test-bb
 ] unit-test
diff --git a/basis/compiler/tests/optimizer.factor b/basis/compiler/tests/optimizer.factor
index 32f5750cd3..0831d6e8dd 100644
--- a/basis/compiler/tests/optimizer.factor
+++ b/basis/compiler/tests/optimizer.factor
@@ -202,7 +202,7 @@ USE: binary-search.private
     dup length 1 <= [
         from>>
     ] [
-        [ midpoint swap call ] 3keep roll dup zero?
+        [ midpoint swap call ] 3keep [ rot ] dip swap dup zero?
         [ drop dup from>> swap midpoint@ + ]
         [ drop dup midpoint@ head-slice old-binsearch ] if
     ] if ; inline recursive
diff --git a/core/layouts/layouts.factor b/core/layouts/layouts.factor
index 426bd560bf..7518dbf0cb 100644
--- a/core/layouts/layouts.factor
+++ b/core/layouts/layouts.factor
@@ -53,7 +53,7 @@ SYMBOL: mega-cache-size
     first-bignum neg >fixnum ; inline
 
 : (max-array-capacity) ( b -- n )
-    5 - 2^ 1 - ; inline
+    6 - 2^ 1 - ; inline
 
 : max-array-capacity ( -- n )
     cell-bits (max-array-capacity) ; inline