diff --git a/gc.c b/gc.c
index 6e42f8ce..6f58fdd6 100644
--- a/gc.c
+++ b/gc.c
@@ -386,7 +386,7 @@ int gc_grow_heap(gc_heap *h, int heap_type, size_t size, size_t chunk_size)
 // so for now it is not used. If it is used again, the initial heaps will
 // need to start at a lower size (EG 1 MB).
   {
-    size_t prev_size = 0 * 1024 * 1024;
+    size_t prev_size = 2 * 1024 * 1024;
     new_size = 0;
     h_last = h;
     while (h_last->next) {
diff --git a/runtime.c b/runtime.c
index b42f3f91..80da55d5 100644
--- a/runtime.c
+++ b/runtime.c
@@ -164,7 +164,7 @@ static bool set_insert(ck_hs_t *hs, const void *value)
 
 void gc_init_heap(long heap_size)
 {
-  size_t initial_heap_size = 1 * 1024 * 1024;
+  size_t initial_heap_size = 3 * 1024 * 1024;
   Cyc_heap = malloc(sizeof(gc_heap_root));
   Cyc_heap->heap = gc_heap_create(HEAP_REST, initial_heap_size, 0, 0);
   Cyc_heap->small_obj_heap = gc_heap_create(HEAP_SM, initial_heap_size, 0, 0);