diff --git a/test-suite/tests/numbers.test b/test-suite/tests/numbers.test
index 880ffdddf..cfb495c1f 100644
--- a/test-suite/tests/numbers.test
+++ b/test-suite/tests/numbers.test
@@ -71,6 +71,34 @@
       (quotient (- n d -1) d)  ;; neg/pos
       (quotient n d)))         ;; pos/pos
 
+;;;
+;;; 1+
+;;;
+
+(with-test-prefix "1+"
+
+  (pass-if "documented?"
+    (documented? 1+))
+
+  (pass-if (eqv? 1 (1+ 0)))
+  (pass-if (eqv? 0 (1+ -1)))
+  (pass-if (eqv? 101 (1+ 100)))
+  (pass-if (eqv? -99 (1+ -100))))
+
+;;;
+;;; 1-
+;;;
+
+(with-test-prefix "1-"
+
+  (pass-if "documented?"
+    (documented? 1-))
+
+  (pass-if (eqv? -1 (1- 0)))
+  (pass-if (eqv? 0 (1- 1)))
+  (pass-if (eqv? 99 (1- 100)))
+  (pass-if (eqv? -101 (1- -100))))
+
 ;;;
 ;;; ash
 ;;;