diff --git a/lib/init-7.scm b/lib/init-7.scm
index e915b693..311f46e7 100644
--- a/lib/init-7.scm
+++ b/lib/init-7.scm
@@ -346,22 +346,31 @@
 (define (char-upper-case? ch) (<= 65 (char->integer ch) 90))
 (define (char-lower-case? ch) (<= 97 (char->integer ch) 122))
 
-(define (char=? a b) (= (char->integer a) (char->integer b)))
-(define (char<? a b) (< (char->integer a) (char->integer b)))
-(define (char>? a b) (> (char->integer a) (char->integer b)))
-(define (char<=? a b) (<= (char->integer a) (char->integer b)))
-(define (char>=? a b) (>= (char->integer a) (char->integer b)))
+(define (char-cmp op a ls)
+  (let lp ((op op) (a (char->integer a)) (ls ls))
+    (if (null? ls)
+        #t
+        (let ((b (char->integer (car ls))))
+          (and (op a b) (lp op b (cdr ls)))))))
 
-(define (char-ci=? a b)
-  (= (char->integer (char-downcase a)) (char->integer (char-downcase b))))
-(define (char-ci<? a b)
-  (< (char->integer (char-downcase a)) (char->integer (char-downcase b))))
-(define (char-ci>? a b)
-  (> (char->integer (char-downcase a)) (char->integer (char-downcase b))))
-(define (char-ci<=? a b)
-  (<= (char->integer (char-downcase a)) (char->integer (char-downcase b))))
-(define (char-ci>=? a b)
-  (>= (char->integer (char-downcase a)) (char->integer (char-downcase b))))
+(define (char=? a . ls) (char-cmp = a ls))
+(define (char<? a . ls) (char-cmp < a ls))
+(define (char>? a . ls) (char-cmp > a ls))
+(define (char<=? a . ls) (char-cmp <= a ls))
+(define (char>=? a . ls) (char-cmp >= a ls))
+
+(define (char-cmp-ci op a ls)
+  (let lp ((op op) (a (char->integer (char-downcase a))) (ls ls))
+    (if (null? ls)
+        #t
+        (let ((b (char->integer (char-downcase (car ls)))))
+          (and (op a b) (lp op b (cdr ls)))))))
+
+(define (char-ci=? a . ls) (char-cmp-ci = a ls))
+(define (char-ci<? a . ls) (char-cmp-ci < a ls))
+(define (char-ci>? a . ls) (char-cmp-ci > a ls))
+(define (char-ci<=? a . ls) (char-cmp-ci <= a ls))
+(define (char-ci>=? a . ls) (char-cmp-ci >= a ls))
 
 ;; string utils
 
diff --git a/lib/scheme/char/full.scm b/lib/scheme/char/full.scm
index c62da9a9..a748c56b 100644
--- a/lib/scheme/char/full.scm
+++ b/lib/scheme/char/full.scm
@@ -49,11 +49,18 @@
         (integer->char (- n (cdar ls))))
        (else (lp (cdr ls)))))))
 
-(define (char-ci<=? a b) (char<=? (char-foldcase a) (char-foldcase b)))
-(define (char-ci<? a b) (char<? (char-foldcase a) (char-foldcase b)))
-(define (char-ci=? a b) (char=? (char-foldcase a) (char-foldcase b)))
-(define (char-ci>=? a b) (char>=? (char-foldcase a) (char-foldcase b)))
-(define (char-ci>? a b) (char>? (char-foldcase a) (char-foldcase b)))
+(define (char-cmp-ci op a ls)
+  (let lp ((op op) (a (char->integer (char-foldcase a))) (ls ls))
+    (if (null? ls)
+        #t
+        (let ((b (char->integer (char-downcase (car ls)))))
+          (and (op a b) (lp op b (cdr ls)))))))
+
+(define (char-ci=? a . ls) (char-cmp-ci = a ls))
+(define (char-ci<? a . ls) (char-cmp-ci < a ls))
+(define (char-ci>? a . ls) (char-cmp-ci > a ls))
+(define (char-ci<=? a . ls) (char-cmp-ci <= a ls))
+(define (char-ci>=? a . ls) (char-cmp-ci >= a ls))
 
 (define (string-downcase str)
   (string-map char-downcase str))
diff --git a/tests/r7rs-tests.scm b/tests/r7rs-tests.scm
index 2ea30edb..a2e4282c 100644
--- a/tests/r7rs-tests.scm
+++ b/tests/r7rs-tests.scm
@@ -870,36 +870,36 @@
 (test #f (char? 'a))
 (test #f (char? 0))
 
-(test #t (char=? #\a #\a))
+(test #t (char=? #\a #\a #\a))
 (test #f (char=? #\a #\A))
-(test #t (char<? #\a #\b))
+(test #t (char<? #\a #\b #\c))
 (test #f (char<? #\a #\a))
 (test #f (char<? #\b #\a))
 (test #f (char>? #\a #\b))
 (test #f (char>? #\a #\a))
-(test #t (char>? #\b #\a))
-(test #t (char<=? #\a #\b))
+(test #t (char>? #\c #\b #\a))
+(test #t (char<=? #\a #\b #\b))
 (test #t (char<=? #\a #\a))
 (test #f (char<=? #\b #\a))
 (test #f (char>=? #\a #\b))
 (test #t (char>=? #\a #\a))
-(test #t (char>=? #\b #\a))
+(test #t (char>=? #\b #\b #\a))
 
 (test #t (char-ci=? #\a #\a))
-(test #t (char-ci=? #\a #\A))
+(test #t (char-ci=? #\a #\A #\a))
 (test #f (char-ci=? #\a #\b))
-(test #t (char-ci<? #\a #\B))
+(test #t (char-ci<? #\a #\B #\c))
 (test #f (char-ci<? #\A #\a))
 (test #f (char-ci<? #\b #\A))
 (test #f (char-ci>? #\A #\b))
 (test #f (char-ci>? #\a #\A))
-(test #t (char-ci>? #\B #\a))
-(test #t (char-ci<=? #\a #\B))
+(test #t (char-ci>? #\c #\B #\a))
+(test #t (char-ci<=? #\a #\B #\b))
 (test #t (char-ci<=? #\A #\a))
 (test #f (char-ci<=? #\b #\A))
 (test #f (char-ci>=? #\A #\b))
 (test #t (char-ci>=? #\a #\A))
-(test #t (char-ci>=? #\B #\a))
+(test #t (char-ci>=? #\b #\B #\a))
 
 (test #t (char-alphabetic? #\a))
 (test #f (char-alphabetic? #\space))