diff --git a/heap-objects.h b/heap-objects.h
index d76d5ee36..14ec2e3d8 100644
--- a/heap-objects.h
+++ b/heap-objects.h
@@ -16,12 +16,4 @@ enum alloc_kind {
 };
 #undef DEFINE_ENUM
 
-#define DEFINE_METHODS(name, Name, NAME) \
-  static inline size_t name##_size(Name *obj) GC_ALWAYS_INLINE; \
-  static inline void visit_##name##_fields(Name *obj,\
-                                           void (*visit)(struct gc_edge edge, void *visit_data), \
-                                           void *visit_data) GC_ALWAYS_INLINE;
-FOR_EACH_HEAP_OBJECT_KIND(DEFINE_METHODS)
-#undef DEFINE_METHODS
-
 #endif // HEAP_OBJECTS_H
diff --git a/mt-gcbench-embedder.h b/mt-gcbench-embedder.h
new file mode 100644
index 000000000..63076f474
--- /dev/null
+++ b/mt-gcbench-embedder.h
@@ -0,0 +1,44 @@
+#ifndef MT_GCBENCH_EMBEDDER_H
+#define MT_GCBENCH_EMBEDDER_H
+
+#include "mt-gcbench-types.h"
+
+#define DEFINE_METHODS(name, Name, NAME) \
+  static inline size_t name##_size(Name *obj) GC_ALWAYS_INLINE; \
+  static inline void visit_##name##_fields(Name *obj,\
+                                           void (*visit)(struct gc_edge edge, void *visit_data), \
+                                           void *visit_data) GC_ALWAYS_INLINE;
+FOR_EACH_HEAP_OBJECT_KIND(DEFINE_METHODS)
+#undef DEFINE_METHODS
+
+static inline size_t node_size(Node *obj) {
+  return sizeof(Node);
+}
+static inline size_t double_array_size(DoubleArray *array) {
+  return sizeof(*array) + array->length * sizeof(double);
+}
+static inline size_t hole_size(Hole *hole) {
+  return sizeof(*hole) + hole->length * sizeof(uintptr_t);
+}
+static inline void
+visit_node_fields(Node *node,
+                  void (*visit)(struct gc_edge edge, void *visit_data),
+                  void *visit_data) {
+  visit(gc_edge(&node->left), visit_data);
+  visit(gc_edge(&node->right), visit_data);
+}
+static inline void
+visit_double_array_fields(DoubleArray *obj,
+                          void (*visit)(struct gc_edge edge, void *visit_data),
+                          void *visit_data) {
+}
+static inline void
+visit_hole_fields(Hole *obj,
+                  void (*visit)(struct gc_edge edge, void *visit_data),
+                  void *visit_data) {
+  abort();
+}
+
+#include "simple-gc-embedder.h"
+
+#endif // MT_GCBENCH_EMBEDDER_H
diff --git a/mt-gcbench-types.h b/mt-gcbench-types.h
index 04bf6d258..32471d025 100644
--- a/mt-gcbench-types.h
+++ b/mt-gcbench-types.h
@@ -7,5 +7,25 @@
   M(hole, Hole, HOLE)
 
 #include "heap-objects.h"
+#include "simple-tagging-scheme.h"
+
+struct Node {
+  struct gc_header header;
+  struct Node *left;
+  struct Node *right;
+  int i, j;
+};
+
+struct DoubleArray {
+  struct gc_header header;
+  size_t length;
+  double values[0];
+};
+
+struct Hole {
+  struct gc_header header;
+  size_t length;
+  uintptr_t values[0];
+};
 
 #endif // GCBENCH_TYPES_H
diff --git a/mt-gcbench.c b/mt-gcbench.c
index 418851ede..4d304c636 100644
--- a/mt-gcbench.c
+++ b/mt-gcbench.c
@@ -44,14 +44,13 @@
 #include <stdlib.h>
 #include <sys/time.h>
 
-// Tracer will be specialized with respect to tags defined in this header.
 #include "mt-gcbench-types.h"
 
 #include "assert.h"
 #include "simple-allocator.h"
-#include "simple-gc-embedder.h"
 #include "gc-api.h"
 
+#include "mt-gcbench-embedder.h"
 #include "gc.h"
 
 #include "gc-inline.h"
@@ -63,53 +62,6 @@ static const int array_size = 500000; // about 4Mb
 static const int min_tree_depth = 4;
 static const int max_tree_depth = 16;
 
-struct Node {
-  struct gc_header header;
-  struct Node *left;
-  struct Node *right;
-  int i, j;
-};
-
-struct DoubleArray {
-  struct gc_header header;
-  size_t length;
-  double values[0];
-};
-
-struct Hole {
-  struct gc_header header;
-  size_t length;
-  uintptr_t values[0];
-};
-
-static inline size_t node_size(Node *obj) {
-  return sizeof(Node);
-}
-static inline size_t double_array_size(DoubleArray *array) {
-  return sizeof(*array) + array->length * sizeof(double);
-}
-static inline size_t hole_size(Hole *hole) {
-  return sizeof(*hole) + hole->length * sizeof(uintptr_t);
-}
-static inline void
-visit_node_fields(Node *node,
-                  void (*visit)(struct gc_edge edge, void *visit_data),
-                  void *visit_data) {
-  visit(gc_edge(&node->left), visit_data);
-  visit(gc_edge(&node->right), visit_data);
-}
-static inline void
-visit_double_array_fields(DoubleArray *obj,
-                          void (*visit)(struct gc_edge edge, void *visit_data),
-                          void *visit_data) {
-}
-static inline void
-visit_hole_fields(Hole *obj,
-                  void (*visit)(struct gc_edge edge, void *visit_data),
-                  void *visit_data) {
-  abort();
-}
-
 typedef HANDLE_TO(Node) NodeHandle;
 typedef HANDLE_TO(DoubleArray) DoubleArrayHandle;
 
diff --git a/quads-embedder.h b/quads-embedder.h
new file mode 100644
index 000000000..18047607c
--- /dev/null
+++ b/quads-embedder.h
@@ -0,0 +1,28 @@
+#ifndef QUADS_EMBEDDER_H
+#define QUADS_EMBEDDER_H
+
+#include "quads-types.h"
+
+#define DEFINE_METHODS(name, Name, NAME) \
+  static inline size_t name##_size(Name *obj) GC_ALWAYS_INLINE; \
+  static inline void visit_##name##_fields(Name *obj,\
+                                           void (*visit)(struct gc_edge edge, void *visit_data), \
+                                           void *visit_data) GC_ALWAYS_INLINE;
+FOR_EACH_HEAP_OBJECT_KIND(DEFINE_METHODS)
+#undef DEFINE_METHODS
+
+static inline size_t quad_size(Quad *obj) {
+  return sizeof(Quad);
+}
+
+static inline void
+visit_quad_fields(Quad *quad,
+                  void (*visit)(struct gc_edge edge, void *visit_data),
+                  void *visit_data) {
+  for (size_t i = 0; i < 4; i++)
+    visit(gc_edge(&quad->kids[i]), visit_data);
+}
+
+#include "simple-gc-embedder.h"
+
+#endif // QUADS_EMBEDDER_H
diff --git a/quads-types.h b/quads-types.h
index 16a1c62d0..935591ef2 100644
--- a/quads-types.h
+++ b/quads-types.h
@@ -5,5 +5,11 @@
   M(quad, Quad, QUAD)
 
 #include "heap-objects.h"
+#include "simple-tagging-scheme.h"
+
+struct Quad {
+  struct gc_header header;
+  struct Quad *kids[4];
+};
 
 #endif // QUADS_TYPES_H
diff --git a/quads.c b/quads.c
index d7438a486..7797bbd42 100644
--- a/quads.c
+++ b/quads.c
@@ -5,23 +5,11 @@
 #include "assert.h"
 #include "quads-types.h"
 #include "simple-allocator.h"
-#include "simple-gc-embedder.h"
+#include "gc-api.h"
+
+#include "quads-embedder.h"
 #include "gc.h"
 
-typedef struct Quad {
-  struct gc_header header;
-  struct Quad *kids[4];
-} Quad;
-static inline size_t quad_size(Quad *obj) {
-  return sizeof(Quad);
-}
-static inline void
-visit_quad_fields(Quad *quad,
-                  void (*visit)(struct gc_edge edge, void *visit_data),
-                  void *visit_data) {
-  for (size_t i = 0; i < 4; i++)
-    visit(gc_edge(&quad->kids[i]), visit_data);
-}
 typedef HANDLE_TO(Quad) QuadHandle;
 
 static Quad* allocate_quad(struct mutator *mut) {