diff --git a/src/6model/repr_registry.c b/src/6model/repr_registry.c
index d01a68ed73..8b86cd5e73 100644
--- a/src/6model/repr_registry.c
+++ b/src/6model/repr_registry.c
@@ -96,16 +96,16 @@ static void default_bind_pos_boxed(PARROT_INTERP, STable *st, void *data, INTVAL
 static INTVAL default_elems(PARROT_INTERP, STable *st, void *data) {
     die_no_idx(interp, st->REPR->name);
 }
-static void default_preallocate(PARROT_INTERP, STable *st, void *data, INTVAL count) {
+static void default_push_boxed(PARROT_INTERP, STable *st, void *data, PMC *obj) {
     die_no_idx(interp, st->REPR->name);
 }
-static void default_trim_to(PARROT_INTERP, STable *st, void *data, INTVAL count) {
+static PMC * default_pop_boxed(PARROT_INTERP, STable *st, void *data) {
     die_no_idx(interp, st->REPR->name);
 }
-static void default_make_hole(PARROT_INTERP, STable *st, void *data, INTVAL at_index, INTVAL count) {
+static void default_unshift_boxed(PARROT_INTERP, STable *st, void *data, PMC *obj) {
     die_no_idx(interp, st->REPR->name);
 }
-static void default_delete_elems(PARROT_INTERP, STable *st, void *data, INTVAL at_index, INTVAL count) {
+static PMC * default_shift_boxed(PARROT_INTERP, STable *st, void *data) {
     die_no_idx(interp, st->REPR->name);
 }
 static STable * default_get_elem_stable(PARROT_INTERP, STable *st) {
@@ -143,6 +143,10 @@ static void add_default_pos_funcs(PARROT_INTERP, REPROps *repr) {
     repr->pos_funcs->bind_pos_native = default_bind_pos_native;
     repr->pos_funcs->bind_pos_boxed = default_bind_pos_boxed;
     repr->pos_funcs->elems = default_elems;
+    repr->pos_funcs->push_boxed = default_push_boxed;
+    repr->pos_funcs->pop_boxed = default_pop_boxed;
+    repr->pos_funcs->unshift_boxed = default_unshift_boxed;
+    repr->pos_funcs->shift_boxed = default_shift_boxed;
     repr->pos_funcs->get_elem_stable = default_get_elem_stable;
 }
 
diff --git a/src/6model/reprs/CArray.c b/src/6model/reprs/CArray.c
index c5995f3556..5d1f46b93a 100644
--- a/src/6model/reprs/CArray.c
+++ b/src/6model/reprs/CArray.c
@@ -201,9 +201,9 @@ static storage_spec get_storage_spec(PARROT_INTERP, STable *st) {
 }
 
 PARROT_DOES_NOT_RETURN
-static void die_idx_nyi(PARROT_INTERP) {
+static void die_pos_nyi(PARROT_INTERP) {
     Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_INVALID_OPERATION,
-        "CArray representation does not fully indexed storage yet");
+        "CArray representation does not fully positional storage yet");
 }
 static void expand(PARROT_INTERP, CArrayREPRData *repr_data, CArrayBody *body, INTVAL min_size) {
     INTVAL is_complex = 0;
@@ -453,6 +453,18 @@ static STable * get_elem_stable(PARROT_INTERP, STable *st) {
     CArrayREPRData *repr_data = (CArrayREPRData *)st->REPR_data;
     return STABLE(repr_data->elem_type);
 }
+static void push_boxed(PARROT_INTERP, STable *st, void *data, PMC *obj) {
+    die_pos_nyi(interp);
+}
+static PMC * pop_boxed(PARROT_INTERP, STable *st, void *data) {
+    die_pos_nyi(interp);
+}
+static void unshift_boxed(PARROT_INTERP, STable *st, void *data, PMC *obj) {
+    die_pos_nyi(interp);
+}
+static PMC * shift_boxed(PARROT_INTERP, STable *st, void *data) {
+    die_pos_nyi(interp);
+}
 
 /* Serializes the REPR data. */
 static void serialize_repr_data(PARROT_INTERP, STable *st, SerializationWriter *writer) {
@@ -496,6 +508,10 @@ REPROps * CArray_initialize(PARROT_INTERP,
     this_repr->pos_funcs->bind_pos_native = bind_pos_native;
     this_repr->pos_funcs->bind_pos_boxed = bind_pos_boxed;
     this_repr->pos_funcs->elems = elems;
+    this_repr->pos_funcs->push_boxed = push_boxed;
+    this_repr->pos_funcs->pop_boxed = pop_boxed;
+    this_repr->pos_funcs->unshift_boxed = unshift_boxed;
+    this_repr->pos_funcs->shift_boxed = shift_boxed;
     this_repr->pos_funcs->get_elem_stable = get_elem_stable;
     this_repr->serialize_repr_data = serialize_repr_data;
     this_repr->deserialize_repr_data = deserialize_repr_data;
diff --git a/src/6model/sixmodelobject.h b/src/6model/sixmodelobject.h
index 956b265693..a19f5f5e56 100644
--- a/src/6model/sixmodelobject.h
+++ b/src/6model/sixmodelobject.h
@@ -258,7 +258,19 @@ typedef struct SixModel_REPROps_Positional {
 
     /* Gets the number of elements. */
     INTVAL (*elems) (PARROT_INTERP, STable *st, void *data);
-
+    
+    /* Pushes an object. */
+    void (*push_boxed) (PARROT_INTERP, STable *st, void *data, PMC *obj);
+    
+    /* Pops an object. */
+    PMC * (*pop_boxed) (PARROT_INTERP, STable *st, void *data);
+    
+    /* Unshifts an object. */
+    void (*unshift_boxed) (PARROT_INTERP, STable *st, void *data, PMC *obj);
+    
+    /* Shifts an object. */
+    PMC * (*shift_boxed) (PARROT_INTERP, STable *st, void *data);
+    
     /* Gets the STable representing the declared element type. */
     STable * (*get_elem_stable) (PARROT_INTERP, STable *st);
 } REPROps_Positional;