diff --git a/lib/srfi/38.scm b/lib/srfi/38.scm
index a25e96f9..149d1948 100644
--- a/lib/srfi/38.scm
+++ b/lib/srfi/38.scm
@@ -158,11 +158,15 @@
             (shared '()))
         (define (read-label res)
           (let ((c (peek-char in)))
-            (if (and (not (eof-object? c))
-                     (or (char-numeric? c)
-                         (memv (char-downcase c) '(#\a #\b #\c #\d #\e #\f))))
-                (read-label (cons (read-char in) res))
-                (list->string (reverse res)))))
+            (cond
+             ((and (not (eof-object? c))
+                   (or (char-numeric? c)
+                       (memv (char-downcase c) '(#\a #\b #\c #\d #\e #\f))))
+              (read-label (cons (read-char in) res)))
+             ((and (memv c '(#\+ #\-)) (null? res))
+              (read-label (cons (read-char in) res)))
+             (else
+              (list->string (reverse res))))))
         (define (read-number base)
           (let* ((str (read-label '()))
                  (n (string->number str base))