diff --git a/racket/src/ChezScheme/mats/fx.ms b/racket/src/ChezScheme/mats/fx.ms
index 145d61e4b4..a7c18e66e2 100644
--- a/racket/src/ChezScheme/mats/fx.ms
+++ b/racket/src/ChezScheme/mats/fx.ms
@@ -480,6 +480,8 @@
    (eqv? (fx+/wraparound (most-negative-fixnum) -2) (sub1 (most-positive-fixnum)))
    (eqv? (fx+/wraparound (most-positive-fixnum) (most-positive-fixnum)) -2)
    (eqv? (fx+/wraparound (most-negative-fixnum) (most-negative-fixnum)) 0)
+   (eqv? (fx+/wraparound (collect-maximum-generation) 0) (collect-maximum-generation))
+   (eqv? (fx+/wraparound 0 (collect-maximum-generation)) (collect-maximum-generation))
    )
 
 (mat fx-
@@ -565,6 +567,7 @@
    (eqv? (fx-/wraparound (most-positive-fixnum) -2) (add1 (most-negative-fixnum)))
    (eqv? (fx-/wraparound (most-positive-fixnum) (most-negative-fixnum)) -1)
    (eqv? (fx-/wraparound (most-negative-fixnum) (most-positive-fixnum)) 1)
+   (eqv? (fx-/wraparound (collect-maximum-generation) 0) (collect-maximum-generation))
    )
 
 (mat fx*
@@ -639,6 +642,8 @@
    (eqv? (fx*/wraparound (most-positive-fixnum) -2) 2)
    (eqv? (fx*/wraparound (most-positive-fixnum) (most-negative-fixnum)) (most-negative-fixnum))
    (eqv? (fx*/wraparound (most-negative-fixnum) (most-positive-fixnum)) (most-negative-fixnum))
+   (eqv? (fx*/wraparound (collect-maximum-generation) 1) (collect-maximum-generation))
+   (eqv? (fx*/wraparound 1 (collect-maximum-generation)) (collect-maximum-generation))
    )
 
 (mat fxquotient
diff --git a/racket/src/ChezScheme/s/cp0.ss b/racket/src/ChezScheme/s/cp0.ss
index acc757256f..8a963417f4 100644
--- a/racket/src/ChezScheme/s/cp0.ss
+++ b/racket/src/ChezScheme/s/cp0.ss
@@ -2606,7 +2606,11 @@
                         [(eqv? a ident)
                          (if (and (fx= level 3) (null? (cdr val*)) (direct-result? (car val*)))
                              (car val*)
-                             (build-primcall (app-preinfo ctxt) level prim val*))]
+                             (if (and (null? (cdr val*))
+                                      ;; `op` may require exactly 2 arguments
+                                      (eqv? (procedure-arity-mask op) 4))
+                                 (build-primcall (app-preinfo ctxt) level prim (cons `(quote ,ident) val*))
+                                 (build-primcall (app-preinfo ctxt) level prim val*)))]
                         [else
                           (build-primcall (app-preinfo ctxt) level prim (cons `(quote ,a) val*))])]))
                 (let* ([arg (car arg*)] [val (value-visit-operand! arg)])