diff --git a/include/xo/alloc/GC.hpp b/include/xo/alloc/GC.hpp
index abbb9657..ce7b0f85 100644
--- a/include/xo/alloc/GC.hpp
+++ b/include/xo/alloc/GC.hpp
@@ -37,14 +37,14 @@ namespace xo {
              *  pages are committed on demand.
              *  Initial committment will be up to @ref incr_gc_threshold_
              **/
-            std::size_t initial_nursery_z_ = 0;
+            std::size_t initial_nursery_z_ = 64*1024*1024;
             /** initial size in bytes for oldest (Tenured) generation.
              *  GC allocates two tenured spaces of this size.
              *  This number represents reserved address space.
              *  pages are committed on demand.
              *  Initial committment will be up to @ref full_gc_threshold_
              **/
-            std::size_t initial_tenured_z_ = 0;
+            std::size_t initial_tenured_z_ = 128*1024*1024;
             /** trigger incremental GC after this many bytes allocated in nursery **/
             std::size_t incr_gc_threshold_ = 64*1024;
             /** trigger full GC after this many bytes promoted to tenured **/
diff --git a/src/alloc/GC.cpp b/src/alloc/GC.cpp
index 8181cbb1..22654700 100644
--- a/src/alloc/GC.cpp
+++ b/src/alloc/GC.cpp
@@ -73,7 +73,7 @@ namespace xo {
             }
 
             if (nursery_size + config_.full_gc_threshold_ > tenured_size) {
-                throw std::runtime_error(tostr("GC::ctor: expected nursery size + tennured gc threshold < tenured size",
+                throw std::runtime_error(tostr("GC::ctor: expected nursery size + tenured gc threshold < tenured size",
                                                xtag("nursery-size", nursery_size),
                                                xtag("tenured-size", tenured_size),
                                                xtag("full-gc-threshold", config_.full_gc_threshold_)