diff --git a/lib/chibi/ast.c b/lib/chibi/ast.c
index 51df718d..9a245902 100644
--- a/lib/chibi/ast.c
+++ b/lib/chibi/ast.c
@@ -677,7 +677,6 @@ sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char
   sexp_define_type_predicate(ctx, env, "ref?", SEXP_REF);
   sexp_define_type_predicate(ctx, env, "seq?", SEXP_SEQ);
   sexp_define_type_predicate(ctx, env, "lit?", SEXP_LIT);
-  sexp_define_type_predicate(ctx, env, "opcode?", SEXP_OPCODE);
   sexp_define_type_predicate(ctx, env, "type?", SEXP_TYPE);
   sexp_define_type_predicate(ctx, env, "core?", SEXP_CORE);
   sexp_define_type_predicate(ctx, env, "context?", SEXP_CONTEXT);
diff --git a/lib/chibi/ast.sld b/lib/chibi/ast.sld
index 477b4fba..56171759 100644
--- a/lib/chibi/ast.sld
+++ b/lib/chibi/ast.sld
@@ -26,11 +26,11 @@
    seq-ls seq-ls-set! lit-value lit-value-set!
    exception-kind exception-message exception-irritants exception-source
    opcode-name opcode-num-params opcode-return-type opcode-param-type
-   opcode-class opcode-code opcode-data opcode-variadic?
+   opcode-class opcode-code opcode-data opcode-variadic? opcode?
    macro-procedure macro-env macro-source macro-aux macro-aux-set!
    procedure-code procedure-vars procedure-name procedure-name-set!
    procedure-arity procedure-variadic? procedure-variable-transformer?
-   procedure-flags make-variable-transformer make-procedure
+   procedure-flags make-variable-transformer make-procedure procedure?
    bytecode-name bytecode-literals bytecode-source
    port-line port-line-set! port-source? port-source?-set!
    extend-env env-parent env-parent-set! env-lambda env-lambda-set!
diff --git a/lib/meta-7.scm b/lib/meta-7.scm
index 077369ca..de5f4c63 100644
--- a/lib/meta-7.scm
+++ b/lib/meta-7.scm
@@ -112,19 +112,19 @@
     (if (memq (car x) '(only except rename))
         (let* ((mod-name+imports (%resolve-import (cadr x)))
                (imp-ids (or (cdr mod-name+imports)
-                            (and (not (eq? 'only (car x)))
-                                 (module-exports
-                                  (find-module (car mod-name+imports)))))))
+                            (module-exports (find-module (car mod-name+imports))))))
           (cons (car mod-name+imports)
                 (case (car x)
                   ((only)
-                   (if imp-ids
-                       (map (lambda (imp) (or (assq imp imp-ids) imp))
-                            (cddr x))
-                       (cddr x)))
+                   (map (lambda (imp)
+                          (if (or (boolean? imp-ids) (memq imp imp-ids))
+                              imp
+                              (error "importing unknown binding" imp imp-ids)))
+                        (cddr x)))
                   ((except)
                    (id-filter (lambda (i) (not (memq i (cddr x)))) imp-ids))
                   ((rename)
+                   ;; TODO: warn about renaming an unimported id
                    (map (lambda (i)
                           (let ((rename (assq (to-id i) (cddr x))))
                             (if rename (cons (cadr rename) (from-id i)) i)))