diff --git a/src/command-line.scm b/src/command-line.scm
index 9d3e1c2..b677587 100644
--- a/src/command-line.scm
+++ b/src/command-line.scm
@@ -84,8 +84,7 @@
 
  ;; String representation of procedure arguments.
  (define (procedure->argstring proc)
-   (let* ((info (procedure-information proc))
-	  (args (cdr info))
+   (let* ((args (procedure-arg-names proc))
 	  (argss (sprintf "~A" args)))
      (substring
       (substring argss 0 (- (string-length argss) 1))
diff --git a/src/util-proc.scm b/src/util-proc.scm
index 8d3a360..5e08745 100644
--- a/src/util-proc.scm
+++ b/src/util-proc.scm
@@ -33,6 +33,7 @@
   procedure-arity>?
 
   procedure-num-args
+  procedure-arg-names
   )
 
  (import scheme
@@ -79,4 +80,8 @@
    (let-values (((args rest?) (procedure-arity-info proc)))
      args))
 
+ ;; Returns the formal argument names for given procedure
+ (define (procedure-arg-names proc)
+   (cdr (procedure-information proc)))
+
  )