diff --git a/include/cyclone/runtime-main.h b/include/cyclone/runtime-main.h
index 2ab0b1ab..a0487d0f 100644
--- a/include/cyclone/runtime-main.h
+++ b/include/cyclone/runtime-main.h
@@ -27,7 +27,7 @@ static void Cyc_heap_init(long heap_size)
 #if DEBUG_SHOW_DIAG
   printf("main: Allocating and initializing heap...\n");
 #endif
-  Cyc_heap = gc_heap_create(heap_size / 2, 0, 0);
+  gc_init_heap();
   gc_init_mutators();
   gc_start_collector();
 }
diff --git a/include/cyclone/runtime.h b/include/cyclone/runtime.h
index 9c287782..03475028 100644
--- a/include/cyclone/runtime.h
+++ b/include/cyclone/runtime.h
@@ -84,6 +84,7 @@ object cell_get(object cell);
 extern object Cyc_global_variables;
 int _cyc_argc;
 char **_cyc_argv;
+void Cyc_init_heap(long heap_size);
 object Cyc_get_global_variables();
 object Cyc_get_cvar(object var);
 object Cyc_set_cvar(object var, object value);
diff --git a/runtime.c b/runtime.c
index e8f9dfd6..e8fc4d5e 100644
--- a/runtime.c
+++ b/runtime.c
@@ -90,6 +90,11 @@ char **_cyc_argv = NULL;
 static symbol_type __EOF = {{0}, eof_tag, "", nil}; // symbol_type in lieu of custom type
 const object Cyc_EOF = &__EOF;
 
+void Cyc_init_heap(long heap_size)
+{
+  Cyc_heap = gc_heap_create(heap_size, 0, 0);
+}
+
 gc_heap *Cyc_get_heap()
 {
   return Cyc_heap;