gistfile1.txt

diff --git a/src/core/nativecall.c b/src/core/nativecall.c
index b96af40..37a7f75 100644
--- a/src/core/nativecall.c
+++ b/src/core/nativecall.c
@@ -435,6 +435,7 @@ static char callback_handler(DCCallback *cb, DCArgs *cb_args, DCValue *cb_result
 
     /* Build a callsite and arguments buffer. */
     MVMRegister *args = MVM_malloc(data->num_types * sizeof(MVMRegister));
+MVM_gc_allocate_gen2_default_set(data->tc); /*XXX*/
     for (i = 1; i < data->num_types; i++) {
         MVMObject *type     = data->types[i];
         MVMint16   typeinfo = data->typeinfos[i];
@@ -489,6 +490,7 @@ static char callback_handler(DCCallback *cb, DCArgs *cb_args, DCValue *cb_result
                     "Internal error: unhandled dyncall callback argument type");
         }
     }
+MVM_gc_allocate_gen2_default_clear(data->tc); /*XXX*/
 
     /* Call into a nested interpreter (since we already are in one). Need to
      * save a bunch of state around each side of this. */