diff --git a/include/roaring/roaring64.h b/include/roaring/roaring64.h
index 3685fcbb9..304babb5d 100644
--- a/include/roaring/roaring64.h
+++ b/include/roaring/roaring64.h
@@ -8,33 +8,14 @@
 #include <stddef.h>
 #include <stdint.h>
 
-// TODO: This is messy and can likely be improved.
-#if defined(__cplusplus)
-#define ROARING_ART_T ::roaring::internal::art_t
-#define ROARING_ART_VAL_T ::roaring::internal::art_val_t
-#else
-#define ROARING_ART_T art_t
-#define ROARING_ART_VAL_T art_val_t
-#define ROARING_CONTAINER_T void
-#endif
-
 #ifdef __cplusplus
 extern "C" {
 namespace roaring {
 namespace api {
 #endif
 
-typedef struct roaring64_bitmap_s {
-    ROARING_ART_T art;
-    uint8_t flags;
-} roaring64_bitmap_t;
-
-// TODO: Ideally we don't put this in the header.
-typedef struct leaf_s {
-    ROARING_ART_VAL_T _pad;
-    uint8_t typecode;
-    ROARING_CONTAINER_T *container;
-} leaf_t;
+typedef struct roaring64_bitmap_s roaring64_bitmap_t;
+typedef struct roaring64_leaf_s roaring64_leaf_t;
 
 /**
  * A bit of context usable with `roaring64_bitmap_*_bulk()` functions.
@@ -50,7 +31,7 @@ typedef struct leaf_s {
 typedef struct roaring64_bulk_context_s {
     uint8_t high_bytes[ART_KEY_BYTES];
     uint16_t low_bytes;
-    leaf_t *leaf;
+    roaring64_leaf_t *leaf;
 } roaring64_bulk_context_t;
 
 /**
diff --git a/src/roaring64.c b/src/roaring64.c
index ffbbcb9bd..bf02af4a2 100644
--- a/src/roaring64.c
+++ b/src/roaring64.c
@@ -1,4 +1,5 @@
 #include <assert.h>
+#include <roaring/art/art.h>
 #include <roaring/containers/containers.h>
 #include <roaring/roaring64.h>
 #include <stdarg.h>
@@ -41,10 +42,9 @@ using namespace ::roaring::internal;
 
 extern "C" {
 namespace roaring {
-namespace api64 {
+namespace api {
 #endif
 
-// TODO: Figure out how to keep art_t from being exposed in roaring64.h
 // TODO: Iteration.
 //  * Need to create a container iterator which can be used across 32 and 64 bit
 //    bitmaps.
@@ -53,6 +53,22 @@ namespace api64 {
 // TODO: Serialization.
 // TODO: Error on failed allocation.
 
+typedef struct roaring64_bitmap_s {
+    art_t art;
+    uint8_t flags;
+} roaring64_bitmap_t;
+
+// Leaf type of the ART used to keep the high 48 bits of each entry.
+typedef struct roaring64_leaf_s {
+    art_val_t _pad;
+    uint8_t typecode;
+    container_t *container;
+} roaring64_leaf_t;
+
+// Alias to make it easier to work with, since it's an internal-only type
+// anyway.
+typedef struct roaring64_leaf_s leaf_t;
+
 // Splits the given uint64 key into high 48 bit and low 16 bit components.
 // Expects high48_out to be of length ART_KEY_BYTES.
 static inline uint16_t split_key(uint64_t key, uint8_t high48_out[]) {