diff --git a/module/language/tree-il/primitives.scm b/module/language/tree-il/primitives.scm
index 955c7bf25..98633f07a 100644
--- a/module/language/tree-il/primitives.scm
+++ b/module/language/tree-il/primitives.scm
@@ -208,11 +208,11 @@
   (x) x
   (x y) (if (and (const? y)
                  (let ((y (const-exp y)))
-                   (and (exact? y) (= y 1))))
+                   (and (number? y) (exact? y) (= y 1))))
             (1+ x)
             (if (and (const? x)
                      (let ((x (const-exp x)))
-                       (and (exact? x) (= x 1))))
+                       (and (number? y) (exact? x) (= x 1))))
                 (1+ y)
                 (+ x y)))
   (x y z . rest) (+ x (+ y z . rest)))
@@ -226,7 +226,7 @@
   (x) (- 0 x)
   (x y) (if (and (const? y)
                  (let ((y (const-exp y)))
-                   (and (exact? y) (= y 1))))
+                   (and (number? y) (exact? y) (= y 1))))
             (1- x)
             (- x y))
   (x y z . rest) (- x (+ y z . rest)))