diff --git a/core/strings/strings-tests.factor b/core/strings/strings-tests.factor
index 5ab7f1dffe..459ec7b153 100755
--- a/core/strings/strings-tests.factor
+++ b/core/strings/strings-tests.factor
@@ -51,6 +51,9 @@ unit-test
 [ "ab" ] [ 2 "abc" resize-string ] unit-test
 [ "abc\0\0\0" ] [ 6 "abc" resize-string ] unit-test
 
+[ "\u001234b" ] [ 2 "\u001234bc" resize-string ] unit-test
+[ "\u001234bc\0\0\0" ] [ 6 "\u001234bc" resize-string ] unit-test
+
 ! Random tester found this
 [ { "kernel-error" 3 12 -7 } ]
 [ [ 2 -7 resize-string ] catch ] unit-test
@@ -88,3 +91,5 @@ unit-test
 	"\udeadbe" clone
 	CHAR: \u123456 over clone set-first
 ] unit-test
+
+
diff --git a/vm/data_gc.c b/vm/data_gc.c
index 3ca41d602c..601a677920 100755
--- a/vm/data_gc.c
+++ b/vm/data_gc.c
@@ -505,7 +505,6 @@ CELL binary_payload_start(CELL pointer)
 	switch(untag_header(get(pointer)))
 	{
 	/* these objects do not refer to other objects at all */
-	case STRING_TYPE:
 	case FLOAT_TYPE:
 	case BYTE_ARRAY_TYPE:
 	case BIT_ARRAY_TYPE:
@@ -522,6 +521,8 @@ CELL binary_payload_start(CELL pointer)
 		return CELLS * 2;
 	case QUOTATION_TYPE:
 		return sizeof(F_QUOTATION) - CELLS * 2;
+	case STRING_TYPE:
+		return sizeof(F_STRING);
 	/* everything else consists entirely of pointers */
 	default:
 		return unaligned_object_size(pointer);
diff --git a/vm/types.c b/vm/types.c
index 1f0287b1f0..24b5e7ff07 100755
--- a/vm/types.c
+++ b/vm/types.c
@@ -480,7 +480,16 @@ F_STRING* allot_string_internal(CELL capacity)
 void fill_string(F_STRING *string, CELL start, CELL capacity, CELL fill)
 {
 	if(fill == 0)
-		memset((void*)SREF(string,start),'\0',capacity - start);
+	{
+		memset((void *)SREF(string,start),'\0',capacity - start);
+
+		if(string->aux != F)
+		{
+			F_BYTE_ARRAY *aux = untag_object(string->aux);
+			memset((void *)BREF(aux,start * sizeof(u16)),'\0',
+				(capacity - start) * sizeof(u16));
+		}
+	}
 	else
 	{
 		CELL i;
@@ -523,6 +532,19 @@ F_STRING* reallot_string(F_STRING* string, CELL capacity, CELL fill)
 
 	memcpy(new_string + 1,string + 1,to_copy);
 
+	if(string->aux != F)
+	{
+		REGISTER_UNTAGGED(string);
+		REGISTER_UNTAGGED(new_string);
+		F_BYTE_ARRAY *new_aux = allot_byte_array(capacity * sizeof(u16));
+		new_string->aux = tag_object(new_aux);
+		UNREGISTER_UNTAGGED(new_string);
+		UNREGISTER_UNTAGGED(string);
+
+		F_BYTE_ARRAY *aux = untag_object(string->aux);
+		memcpy(new_aux + 1,aux + 1,to_copy * sizeof(u16));
+	}
+
 	REGISTER_UNTAGGED(string);
 	fill_string(new_string,to_copy,capacity,fill);
 	UNREGISTER_UNTAGGED(string);
@@ -573,7 +595,7 @@ DEFINE_PRIMITIVE(resize_string)
 
 MEMORY_TO_STRING(char,u8)
 MEMORY_TO_STRING(u16,u16)
-// MEMORY_TO_STRING(u32,u32)
+MEMORY_TO_STRING(u32,u32)
 
 bool check_string(F_STRING *s, CELL max)
 {
diff --git a/vm/types.h b/vm/types.h
index 6f4234af34..e5003ea069 100755
--- a/vm/types.h
+++ b/vm/types.h
@@ -83,8 +83,8 @@ INLINE CELL array_capacity(F_ARRAY* array)
 	return array->capacity >> TAG_BITS;
 }
 
-#define BREF(byte_array,index) ((CELL)byte_array + sizeof(F_BYTE_ARRAY) + index)
-#define SREF(string,index) ((CELL)string + sizeof(F_STRING) + index)
+#define BREF(byte_array,index) ((CELL)byte_array + sizeof(F_BYTE_ARRAY) + (index))
+#define SREF(string,index) ((CELL)string + sizeof(F_STRING) + (index))
 
 INLINE F_STRING* untag_string(CELL tagged)
 {