diff --git a/ansi.scm b/ansi.scm
index a72f4b9..6c28ac3 100644
--- a/ansi.scm
+++ b/ansi.scm
@@ -155,8 +155,8 @@
  ;; accordingly.
  (define (ansi-paragraph-format str width)
    (let* ((strl (string->list str))
-	  (first-char (car strl))
-	  (last-char (car (reverse strl)))
+	  (first-char (if (null? strl) #f (car strl)))
+	  (last-char (if (null? strl) #f (car (reverse strl))))
 	  (first-tab (eq? first-char #\tab))
 	  (last-tab (eq? last-char #\tab)))
      (let loop ((words (string-split
diff --git a/table.scm b/table.scm
index 83c6684..6ea52e2 100644
--- a/table.scm
+++ b/table.scm
@@ -138,8 +138,12 @@
 
  ;; Normalizes cell line to required width and handles leading and
  ;; trailing tabs to allow for right and center alignment.
- (define (table-normalize-cell-line cs w)
-   (let ((csl (ansi-string-length cs)))
+ (define (table-normalize-cell-line line w)
+   (let ((lst (string->list line))
+	 (first-char (if (null? lst) #f (car lst)))
+	 (last-char (if (null? lst) #f (car (reverse lst))))
+	 ;; Line without tabs
+	 (len (ansi-string-length line)))
      (if (< csl w)
 	 (string-append cs (string-repeat " " (- w csl)))
 	 cs)))