diff --git a/include/jemalloc/internal/extent_inlines.h b/include/jemalloc/internal/extent_inlines.h
index 56f306df..f86822de 100644
--- a/include/jemalloc/internal/extent_inlines.h
+++ b/include/jemalloc/internal/extent_inlines.h
@@ -49,7 +49,7 @@ int extent_snad_comp(const extent_t *a, const extent_t *b);
 #if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_EXTENT_C_))
 JEMALLOC_INLINE arena_t *
 extent_arena_get(const extent_t *extent) {
-	return extent->e_arena;
+	return arenas[extent->e_arena_ind];
 }
 
 JEMALLOC_INLINE void *
@@ -151,7 +151,7 @@ extent_prof_tctx_get(const extent_t *extent) {
 
 JEMALLOC_INLINE void
 extent_arena_set(extent_t *extent, arena_t *arena) {
-	extent->e_arena = arena;
+	extent->e_arena_ind = (arena != NULL) ? arena_ind_get(arena) : UINT_MAX;
 }
 
 JEMALLOC_INLINE void
diff --git a/include/jemalloc/internal/extent_structs.h b/include/jemalloc/internal/extent_structs.h
index 5cf3c9b2..1b2b4bc7 100644
--- a/include/jemalloc/internal/extent_structs.h
+++ b/include/jemalloc/internal/extent_structs.h
@@ -10,8 +10,8 @@ typedef enum {
 
 /* Extent (span of pages).  Use accessor functions for e_* fields. */
 struct extent_s {
-	/* Arena from which this extent came, if any. */
-	arena_t			*e_arena;
+	/* Arena from which this extent came, or UINT_MAX if unassociated. */
+	unsigned		e_arena_ind;
 
 	/* Pointer to the extent that this structure is responsible for. */
 	void			*e_addr;
diff --git a/include/jemalloc/internal/jemalloc_internal.h.in b/include/jemalloc/internal/jemalloc_internal.h.in
index 2fe21018..4255b639 100644
--- a/include/jemalloc/internal/jemalloc_internal.h.in
+++ b/include/jemalloc/internal/jemalloc_internal.h.in
@@ -932,7 +932,6 @@ decay_ticker_get(tsd_t *tsd, unsigned ind) {
 }
 #endif
 
-#include "jemalloc/internal/extent_inlines.h"
 #include "jemalloc/internal/rtree_inlines.h"
 #include "jemalloc/internal/base_inlines.h"
 #include "jemalloc/internal/bitmap_inlines.h"
@@ -942,6 +941,7 @@ decay_ticker_get(tsd_t *tsd, unsigned ind) {
  */
 #include "jemalloc/internal/prof_inlines_a.h"
 #include "jemalloc/internal/arena_inlines_a.h"
+#include "jemalloc/internal/extent_inlines.h"
 
 #ifndef JEMALLOC_ENABLE_INLINE
 extent_t	*iealloc(tsdn_t *tsdn, const void *ptr);