diff --git a/module/rnrs/enums.scm b/module/rnrs/enums.scm
index 79d341746..e97be46e3 100644
--- a/module/rnrs/enums.scm
+++ b/module/rnrs/enums.scm
@@ -82,8 +82,8 @@
 	 (enum-set-subset? enum-set-2 enum-set-1)))
 
   (define (enum-set-union enum-set-1 enum-set-2)
-    (if (eq? (enum-set-universe enum-set-1) 
-	     (enum-set-universe enum-set-2))
+    (if (equal? (enum-set-universe enum-set-1) 
+                (enum-set-universe enum-set-2))
 	(make-enum-set (enum-set-universe enum-set-1)
 		       (lset-union eq? 
 				   (enum-set-set enum-set-1) 
@@ -91,8 +91,8 @@
 	(raise (make-assertion-violation))))
 
   (define (enum-set-intersection enum-set-1 enum-set-2)
-    (if (eq? (enum-set-universe enum-set-1) 
-	     (enum-set-universe enum-set-2))
+    (if (equal? (enum-set-universe enum-set-1) 
+                (enum-set-universe enum-set-2))
 	(make-enum-set (enum-set-universe enum-set-1)
 		       (lset-intersection eq? 
 					  (enum-set-set enum-set-1) 
@@ -100,8 +100,8 @@
 	(raise (make-assertion-violation))))
 
   (define (enum-set-difference enum-set-1 enum-set-2)
-    (if (eq? (enum-set-universe enum-set-1) 
-	     (enum-set-universe enum-set-2))
+    (if (equal? (enum-set-universe enum-set-1) 
+                (enum-set-universe enum-set-2))
 	(make-enum-set (enum-set-universe enum-set-1)
 		       (lset-difference eq? 
 					(enum-set-set enum-set-1) 
diff --git a/test-suite/tests/r6rs-enums.test b/test-suite/tests/r6rs-enums.test
index d91de1c35..4b7d1d72a 100644
--- a/test-suite/tests/r6rs-enums.test
+++ b/test-suite/tests/r6rs-enums.test
@@ -146,7 +146,13 @@
 	   (set1 ((enum-set-constructor universe) '(a b c)))
 	   (set2 ((enum-set-constructor universe) '(d e f)))
 	   (union (enum-set-union set1 set2)))
-      (equal? (enum-set->list union) '(a b c d e f)))))
+      (equal? (enum-set->list union) '(a b c d e f))))
+
+  (pass-if "enum-set-union operates on syntactically-generated sets"
+    (let* ((set1 (make-foo-set foo))
+	   (set2 (make-foo-set bar))
+	   (union (enum-set-union set1 set2)))
+      (equal? (enum-set->list union) '(foo bar)))))
 
 (with-test-prefix "enum-set-intersection"
   (pass-if "&assertion raised on different universes"
@@ -170,7 +176,13 @@
 	   (set1 ((enum-set-constructor universe) '(a b c)))
 	   (set2 ((enum-set-constructor universe) '(d e f)))
 	   (intersection (enum-set-intersection set1 set2)))
-      (null? (enum-set->list intersection)))))
+      (null? (enum-set->list intersection))))
+
+  (pass-if "enum-set-intersection on syntactically-generated sets"
+    (let* ((set1 (make-foo-set foo bar))
+	   (set2 (make-foo-set bar baz))
+	   (intersection (enum-set-intersection set1 set2)))
+      (equal? (enum-set->list intersection) '(bar)))))
 
 (with-test-prefix "enum-set-difference"
   (pass-if "&assertion raised on different universes"
@@ -194,7 +206,13 @@
 	   (set1 ((enum-set-constructor universe) '(a b c)))
 	   (set2 ((enum-set-constructor universe) '(a b c d)))
 	   (difference (enum-set-difference set1 set2)))
-      (null? (enum-set->list difference)))))
+      (null? (enum-set->list difference))))
+
+  (pass-if "enum-set-difference on syntactically-generated sets"
+    (let* ((set1 (make-foo-set foo bar baz))
+	   (set2 (make-foo-set foo baz))
+	   (difference (enum-set-difference set1 set2)))
+      (equal? (enum-set->list difference) '(bar)))))
 
 (with-test-prefix "enum-set-complement"
   (pass-if "complement of empty set is universe"