diff --git a/basis/compiler/cfg/value-numbering/comparisons/comparisons.factor b/basis/compiler/cfg/value-numbering/comparisons/comparisons.factor
index ed037c4d06..8bbacd2f29 100644
--- a/basis/compiler/cfg/value-numbering/comparisons/comparisons.factor
+++ b/basis/compiler/cfg/value-numbering/comparisons/comparisons.factor
@@ -280,21 +280,29 @@ M: ##compare-integer-imm rewrite
 
 M: ##test rewrite
     {
-        { [ dup src1>> vreg>insn ##load-integer? ] [ t >test-imm ] }
-        { [ dup src2>> vreg>insn ##load-integer? ] [ f >test-imm ] }
-        { [ dup diagonal? not ] [ drop f ] }
-        { [ dup src1>> vreg>insn ##and? ] [ simplify-test ] }
-        { [ dup src1>> vreg>insn ##and-imm? ] [ simplify-test-imm ] }
+        { [ dup src1>> vreg-immediate-comparand? ] [ t >test-imm ] }
+        { [ dup src2>> vreg-immediate-comparand? ] [ f >test-imm ] }
+        { [ dup diagonal? ] [
+            {
+                { [ dup src1>> vreg>insn ##and? ] [ simplify-test ] }
+                { [ dup src1>> vreg>insn ##and-imm? ] [ simplify-test-imm ] }
+                [ drop f ]
+            } cond
+        ] }
         [ drop f ]
     } cond ;
 
 M: ##test-branch rewrite
     {
-        { [ dup src1>> vreg>insn ##load-integer? ] [ t >test-imm-branch ] }
-        { [ dup src2>> vreg>insn ##load-integer? ] [ f >test-imm-branch ] }
-        { [ dup diagonal? not ] [ drop f ] }
-        { [ dup src1>> vreg>insn ##and? ] [ simplify-test-branch ] }
-        { [ dup src1>> vreg>insn ##and-imm? ] [ simplify-test-imm-branch ] }
+        { [ dup src1>> vreg-immediate-comparand? ] [ t >test-imm-branch ] }
+        { [ dup src2>> vreg-immediate-comparand? ] [ f >test-imm-branch ] }
+        { [ dup diagonal? ] [
+            {
+                { [ dup src1>> vreg>insn ##and? ] [ simplify-test-branch ] }
+                { [ dup src1>> vreg>insn ##and-imm? ] [ simplify-test-imm-branch ] }
+                [ drop f ]
+            } cond
+        ] }
         [ drop f ]
     } cond ;
 
diff --git a/basis/compiler/cfg/value-numbering/value-numbering-tests.factor b/basis/compiler/cfg/value-numbering/value-numbering-tests.factor
index be387c3f32..ecf6da0894 100644
--- a/basis/compiler/cfg/value-numbering/value-numbering-tests.factor
+++ b/basis/compiler/cfg/value-numbering/value-numbering-tests.factor
@@ -1163,6 +1163,51 @@ cpu x86.32? [
     } value-numbering-step
 ] unit-test
 
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##load-integer f 1 10 }
+        T{ ##test-imm-branch f 0 10 cc= }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##load-integer f 1 10 }
+        T{ ##test-branch f 1 0 cc= }
+    } value-numbering-step
+] unit-test
+
+! Make sure the immediate fits
+cpu x86.64? [
+    [
+        {
+            T{ ##peek f 0 D 0 }
+            T{ ##load-integer f 1 100000000000 }
+            T{ ##test f 2 1 0 cc= }
+        }
+    ] [
+        {
+            T{ ##peek f 0 D 0 }
+            T{ ##load-integer f 1 100000000000 }
+            T{ ##test f 2 1 0 cc= }
+        } value-numbering-step
+    ] unit-test
+
+    [
+        {
+            T{ ##peek f 0 D 0 }
+            T{ ##load-integer f 1 100000000000 }
+            T{ ##test-branch f 1 0 cc= }
+        }
+    ] [
+        {
+            T{ ##peek f 0 D 0 }
+            T{ ##load-integer f 1 100000000000 }
+            T{ ##test-branch f 1 0 cc= }
+        } value-numbering-step
+    ] unit-test
+] when
+
 ! Rewriting ##compare into ##test
 cpu x86? [
     [