diff --git a/libguile/vm-engine.c b/libguile/vm-engine.c
index 61fb38967..63f4b895e 100644
--- a/libguile/vm-engine.c
+++ b/libguile/vm-engine.c
@@ -322,8 +322,6 @@
   VM_VALIDATE (x, SCM_CHARP, proc, char)
 #define VM_VALIDATE_STRING(obj, proc)                                   \
   VM_VALIDATE (obj, scm_is_string, proc, string)
-#define VM_VALIDATE_VARIABLE(obj, proc)                                 \
-  VM_VALIDATE (obj, SCM_VARIABLEP, proc, variable)
 
 #define VM_VALIDATE_INDEX(u64, size, proc)                              \
   VM_ASSERT (u64 < size, vm_error_out_of_range_uint64 (proc, u64))
@@ -1536,34 +1534,11 @@ VM_NAME (scm_i_thread *thread, struct scm_vm *vp,
       NEXT (3);
     }
 
-  /* free-ref dst:12 src:12 _:8 idx:24
-   *
-   * Load free variable IDX from the closure SRC into local slot DST.
-   */
-  VM_DEFINE_OP (55, free_ref, "free-ref", OP2 (X8_S12_S12, X8_C24) | OP_DST)
+  VM_DEFINE_OP (55, unused_55, NULL, NOP)
+  VM_DEFINE_OP (56, unused_56, NULL, NOP)
     {
-      scm_t_uint16 dst, src;
-      scm_t_uint32 idx;
-      UNPACK_12_12 (op, dst, src);
-      UNPACK_24 (ip[1], idx);
-      /* CHECK_FREE_VARIABLE (src); */
-      SP_SET (dst, SCM_PROGRAM_FREE_VARIABLE_REF (SP_REF (src), idx));
-      NEXT (2);
-    }
-
-  /* free-set! dst:12 src:12 _:8 idx:24
-   *
-   * Set free variable IDX from the closure DST to SRC.
-   */
-  VM_DEFINE_OP (56, free_set, "free-set!", OP2 (X8_S12_S12, X8_C24))
-    {
-      scm_t_uint16 dst, src;
-      scm_t_uint32 idx;
-      UNPACK_12_12 (op, dst, src);
-      UNPACK_24 (ip[1], idx);
-      /* CHECK_FREE_VARIABLE (src); */
-      SCM_PROGRAM_FREE_VARIABLE_SET (SP_REF (dst), idx, SP_REF (src));
-      NEXT (2);
+      vm_error_bad_instruction (op);
+      abort (); /* never reached */
     }
 
 
diff --git a/module/language/cps/compile-bytecode.scm b/module/language/cps/compile-bytecode.scm
index f14f48f43..8e6388a29 100644
--- a/module/language/cps/compile-bytecode.scm
+++ b/module/language/cps/compile-bytecode.scm
@@ -172,8 +172,6 @@
          (emit-word-ref/immediate asm (from-sp dst) (from-sp (slot obj)) idx))
         (($ $primcall 'pointer-ref/immediate (annotation . idx) (obj))
          (emit-pointer-ref/immediate asm (from-sp dst) (from-sp (slot obj)) idx))
-        (($ $primcall 'free-ref idx (closure))
-         (emit-free-ref asm (from-sp dst) (from-sp (slot closure)) idx))
         (($ $primcall 'char->integer #f (src))
          (emit-char->integer asm (from-sp dst) (from-sp (slot src))))
         (($ $primcall 'integer->char #f (src))
@@ -302,9 +300,6 @@
         (($ $primcall 'pointer-set!/immediate (annotation . idx) (obj val))
          (emit-pointer-set!/immediate asm (from-sp (slot obj)) idx
                                       (from-sp (slot val))))
-        (($ $primcall 'free-set! idx (closure value))
-         (emit-free-set! asm (from-sp (slot closure)) (from-sp (slot value))
-                         idx))
         (($ $primcall 'string-set! #f (string index char))
          (emit-string-set! asm (from-sp (slot string)) (from-sp (slot index))
                            (from-sp (slot char))))
diff --git a/module/language/cps/effects-analysis.scm b/module/language/cps/effects-analysis.scm
index aea0d5803..3c52225d0 100644
--- a/module/language/cps/effects-analysis.scm
+++ b/module/language/cps/effects-analysis.scm
@@ -450,11 +450,6 @@ the LABELS that are clobbered by the effects of LABEL."
   ((f32-set! obj bv n x)           (&write-object (annotation->memory-kind param)))
   ((f64-set! obj bv n x)           (&write-object (annotation->memory-kind param))))
 
-;; Closures.
-(define-primitive-effects* param
-  ((free-ref closure)              (&read-field &closure param))
-  ((free-set! closure val)         (&write-field &closure param)))
-
 ;; Modules.
 (define-primitive-effects
   ((current-module)                (&read-object &module))
diff --git a/module/system/vm/assembler.scm b/module/system/vm/assembler.scm
index da125119d..33645a28d 100644
--- a/module/system/vm/assembler.scm
+++ b/module/system/vm/assembler.scm
@@ -198,8 +198,6 @@
             emit-bind-kwargs
             emit-bind-rest
             emit-make-closure
-            emit-free-ref
-            emit-free-set!
             emit-current-module
             emit-resolve
             emit-define!
diff --git a/module/system/vm/disassembler.scm b/module/system/vm/disassembler.scm
index 8664039f0..286a0f1c5 100644
--- a/module/system/vm/disassembler.scm
+++ b/module/system/vm/disassembler.scm
@@ -275,8 +275,6 @@ address of that offset."
      (list "~A" (builtin-index->name idx)))
     (((or 'static-ref 'static-set!) _ target)
      (list "~@Y" (dereference-scm target)))
-    (((or 'free-ref 'free-set!) _ _ index)
-     (list "free var ~a" index))
     (('resolve-module dst name public)
      (list "~a" (if (zero? public) "private" "public")))
     (('toplevel-box _ var-offset mod-offset sym-offset bound?)