diff --git a/basis/compiler/tree/modular-arithmetic/modular-arithmetic-tests.factor b/basis/compiler/tree/modular-arithmetic/modular-arithmetic-tests.factor
index 8b7c3a57f5..0e6161078a 100644
--- a/basis/compiler/tree/modular-arithmetic/modular-arithmetic-tests.factor
+++ b/basis/compiler/tree/modular-arithmetic/modular-arithmetic-tests.factor
@@ -21,10 +21,12 @@ IN: compiler.tree.modular-arithmetic.tests
 
 TUPLE: declared-fixnum { x fixnum } ;
 
-[ t ] [
-    [ { declared-fixnum } declare [ 1 + ] change-x ]
-    { + fixnum+ >fixnum } inlined?
-] unit-test
+! XXX: As of .97, we do a bounds check and throw an error on overflow, so we can't
+! use fixnum+ here. If this is too big a regression, we can revert it.
+! [ t ] [
+    ! [ { declared-fixnum } declare [ 1 + ] change-x ]
+    ! { + fixnum+ >fixnum } inlined?
+! ] unit-test
 
 [ t ] [
     [ { declared-fixnum } declare x>> drop ]
diff --git a/basis/compiler/tree/modular-arithmetic/modular-arithmetic.factor b/basis/compiler/tree/modular-arithmetic/modular-arithmetic.factor
index 2aafeebdd8..135a63692d 100644
--- a/basis/compiler/tree/modular-arithmetic/modular-arithmetic.factor
+++ b/basis/compiler/tree/modular-arithmetic/modular-arithmetic.factor
@@ -39,9 +39,7 @@ IN: compiler.tree.modular-arithmetic
 ! is a modular arithmetic word, then the input can be converted into
 ! a form that is cheaper to compute.
 {
-    >fixnum
-    bignum>fixnum bignum>fixnum-strict
-    integer>fixnum integer>fixnum-strict
+    >fixnum bignum>fixnum integer>fixnum
     float>fixnum
     set-alien-unsigned-1 set-alien-signed-1
     set-alien-unsigned-2 set-alien-signed-2
diff --git a/basis/typed/typed-tests.factor b/basis/typed/typed-tests.factor
index 89347cbbb7..2c255e388c 100644
--- a/basis/typed/typed-tests.factor
+++ b/basis/typed/typed-tests.factor
@@ -1,7 +1,7 @@
 USING: accessors effects eval kernel layouts math namespaces
 quotations tools.test typed words words.symbol combinators.short-circuit
 compiler.tree.debugger prettyprint definitions compiler.units sequences
-classes.intersection strings classes.union kernel.private ;
+classes.intersection strings classes.union ;
 IN: typed.tests
 
 TYPED: f+ ( a: float b: float -- c: float )
@@ -13,8 +13,12 @@ TYPED: f+ ( a: float b: float -- c: float )
 TYPED: fix+ ( a: fixnum b: fixnum -- c: fixnum )
     + ;
 
-most-positive-fixnum neg 1 - 1quotation
-[ most-positive-fixnum 1 fix+ ] unit-test
+! XXX: As of .97, we don't require that the output is a fixnum.
+! most-positive-fixnum neg 1 - 1quotation
+! [ most-positive-fixnum 1 fix+ ] unit-test
+
+! XXX: Check that we throw an error. This used to underflow to the least-positive-fixnum.
+[ most-positive-fixnum 1 fix+ ] [ { "kernel-error" 7 } head? ] must-fail-with
 
 TUPLE: tweedle-dee ; final
 TUPLE: tweedle-dum ; final