diff --git a/libguile/programs.c b/libguile/programs.c
index 71abaa750..dfa6196d4 100644
--- a/libguile/programs.c
+++ b/libguile/programs.c
@@ -129,15 +129,19 @@ program_apply (SCM program, SCM args)
 static int
 program_print (SCM program, SCM port, scm_print_state *pstate)
 {
+  static int print_error = 0;
+
   if (SCM_FALSEP (write_program))
     write_program = scm_module_local_variable
       (scm_c_resolve_module ("system vm program"),
        scm_from_locale_symbol ("write-program"));
   
-  if (SCM_FALSEP (write_program))
+  if (SCM_FALSEP (write_program) || print_error)
     return scm_smob_print (program, port, pstate);
 
+  print_error = 1;
   scm_call_2 (SCM_VARIABLE_REF (write_program), program, port);
+  print_error = 0;
   return 1;
 }
 
diff --git a/module/system/vm/program.scm b/module/system/vm/program.scm
index 4be2da10e..f31d5bf31 100644
--- a/module/system/vm/program.scm
+++ b/module/system/vm/program.scm
@@ -82,7 +82,7 @@
   (let ((bindings (program-bindings prog))
         (nargs (arity:nargs (program-arity prog)))
         (rest? (not (zero? (arity:nrest (program-arity prog))))))
-    (if (not bindings)
+    (if (or (null? bindings) (not bindings))
         (if rest? (cons (1- nargs) 1) (list nargs))
         (let ((arg-names (map binding:name (cdar bindings))))
           (if rest?
@@ -92,5 +92,7 @@
 (define (write-program prog port)
   (format port "#<program ~a ~a>"
           (or (program-name prog)
+              (let ((s (program-sources prog)))
+                (and (not (null? s)) (cdar s)))
               (number->string (object-address prog) 16))
           (program-bindings-as-lambda-list prog)))