diff --git a/basis/math/combinatorics/combinatorics.factor b/basis/math/combinatorics/combinatorics.factor
index 5c03e41870..6971d88792 100644
--- a/basis/math/combinatorics/combinatorics.factor
+++ b/basis/math/combinatorics/combinatorics.factor
@@ -1,7 +1,7 @@
 ! Copyright (c) 2007-2009 Slava Pestov, Doug Coleman, Aaron Schaefer.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors assocs binary-search fry kernel locals math math.order
-    math.ranges mirrors namespaces sequences sorting ;
+    math.ranges namespaces sequences sorting ;
 IN: math.combinatorics
 
 <PRIVATE
diff --git a/basis/math/vectors/simd/simd.factor b/basis/math/vectors/simd/simd.factor
index 997fec32fd..43a8d2aa2f 100644
--- a/basis/math/vectors/simd/simd.factor
+++ b/basis/math/vectors/simd/simd.factor
@@ -9,6 +9,8 @@ IN: math.vectors.simd
 
 ERROR: bad-simd-length got expected ;
 
+ERROR: bad-simd-vector obj ;
+
 <<
 <PRIVATE
 ! Primitive SIMD constructors
@@ -239,7 +241,10 @@ c:<c-type>
     byte-array >>class
     A >>boxed-class
     { A-rep alien-vector A boa } >quotation >>getter
-    { [ underlying>> ] 2dip A-rep set-alien-vector } >quotation >>setter
+    {
+        [ dup simd-128? [ bad-simd-vector ] unless underlying>> ] 2dip
+        A-rep set-alien-vector
+    } >quotation >>setter
     16 >>size
     16 >>align
     A-rep >>rep
diff --git a/basis/tools/deploy/shaker/shaker.factor b/basis/tools/deploy/shaker/shaker.factor
index 4e117e11b5..ea02aa03c9 100644
--- a/basis/tools/deploy/shaker/shaker.factor
+++ b/basis/tools/deploy/shaker/shaker.factor
@@ -180,7 +180,6 @@ IN: tools.deploy.shaker
                 "slots"
                 "special"
                 "specializer"
-                "specializations"
                 "struct-slots"
                 ! UI needs this
                 ! "superclass"
diff --git a/vm/data_heap.cpp b/vm/data_heap.cpp
index 7234ffb775..aa7e3eb51a 100755
--- a/vm/data_heap.cpp
+++ b/vm/data_heap.cpp
@@ -98,11 +98,16 @@ void data_heap::reset_generation(tenured_space *gen)
 	clear_decks(gen);
 }
 
-bool data_heap::low_memory_p()
+bool data_heap::high_fragmentation_p()
 {
 	return (tenured->largest_free_block() <= nursery->size + aging->size);
 }
 
+bool data_heap::low_memory_p()
+{
+	return (tenured->free_space() <= nursery->size + aging->size);
+}
+
 void data_heap::mark_all_cards()
 {
 	memset(cards,-1,cards_end - cards);
diff --git a/vm/data_heap.hpp b/vm/data_heap.hpp
index ce156696b8..cef43ef5fe 100755
--- a/vm/data_heap.hpp
+++ b/vm/data_heap.hpp
@@ -29,6 +29,7 @@ struct data_heap {
 	void reset_generation(nursery_space *gen);
 	void reset_generation(aging_space *gen);
 	void reset_generation(tenured_space *gen);
+	bool high_fragmentation_p();
 	bool low_memory_p();
 	void mark_all_cards();
 };
diff --git a/vm/full_collector.cpp b/vm/full_collector.cpp
index 14c7f09332..da7da4a951 100644
--- a/vm/full_collector.cpp
+++ b/vm/full_collector.cpp
@@ -143,12 +143,20 @@ void factor_vm::collect_full(bool trace_contexts_p)
 {
 	collect_mark_impl(trace_contexts_p);
 	collect_sweep_impl();
+
 	if(data->low_memory_p())
+	{
+		current_gc->op = collect_growing_heap_op;
+		current_gc->event->op = collect_growing_heap_op;
+		collect_growing_heap(0,trace_contexts_p);
+	}
+	else if(data->high_fragmentation_p())
 	{
 		current_gc->op = collect_compact_op;
 		current_gc->event->op = collect_compact_op;
 		collect_compact_impl(trace_contexts_p);
 	}
+
 	code->flush_icache();
 }
 
diff --git a/vm/gc.cpp b/vm/gc.cpp
index f90ad58f23..f8a9fd45b8 100755
--- a/vm/gc.cpp
+++ b/vm/gc.cpp
@@ -152,7 +152,7 @@ void factor_vm::gc(gc_op op, cell requested_bytes, bool trace_contexts_p)
 		break;
 	case collect_aging_op:
 		collect_aging();
-		if(data->low_memory_p())
+		if(data->high_fragmentation_p())
 		{
 			current_gc->op = collect_full_op;
 			current_gc->event->op = collect_full_op;
@@ -161,7 +161,7 @@ void factor_vm::gc(gc_op op, cell requested_bytes, bool trace_contexts_p)
 		break;
 	case collect_to_tenured_op:
 		collect_to_tenured();
-		if(data->low_memory_p())
+		if(data->high_fragmentation_p())
 		{
 			current_gc->op = collect_full_op;
 			current_gc->event->op = collect_full_op;