diff --git a/vm/alloc/HeapBitmap.h b/vm/alloc/HeapBitmap.h
index e60d06f..5810d9a 100644
--- a/vm/alloc/HeapBitmap.h
+++ b/vm/alloc/HeapBitmap.h
@@ -50,8 +50,7 @@
     static inline p __attribute__((always_inline)); \
     static inline p
 
-
-struct HeapBitmap {
+typedef struct {
     /* The bitmap data, which points to an mmap()ed area of zeroed
      * anonymous memory.
      */
@@ -78,8 +77,7 @@
      * to a set bit.  If there are no bits set, (max < base).
      */
     uintptr_t max;
-};
-typedef struct HeapBitmap HeapBitmap;
+} HeapBitmap;
 
 typedef void BitmapCallback(size_t numPtrs, void **ptrs,
                             const void *finger, void *arg);