diff --git a/include/jemalloc/internal/arena_structs_b.h b/include/jemalloc/internal/arena_structs_b.h
index 49fdd17d..ebcdbc4d 100644
--- a/include/jemalloc/internal/arena_structs_b.h
+++ b/include/jemalloc/internal/arena_structs_b.h
@@ -36,11 +36,6 @@ struct arena_bin_info_s {
 	bitmap_info_t		bitmap_info;
 };
 
-typedef union {
-	size_t			u; /* Used for atomic operations. */
-	ssize_t			s; /* Time may be negative (means "never"). */
-} arena_decay_time_t;
-
 struct arena_decay_s {
 	/* Synchronizes all non-atomic fields. */
 	malloc_mutex_t		mtx;
@@ -51,7 +46,7 @@ struct arena_decay_s {
 	 *
 	 * Synchronization: atomic.
 	 */
-	arena_decay_time_t	time;
+	ssize_t			time;
 	/* time / SMOOTHSTEP_NSTEPS. */
 	nstime_t		interval;
 	/*
diff --git a/src/arena.c b/src/arena.c
index f4450f34..56ab362d 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -470,16 +470,12 @@ arena_extent_ralloc_large_expand(tsdn_t *tsdn, arena_t *arena, extent_t *extent,
 
 static ssize_t
 arena_decay_time_read(arena_t *arena) {
-	arena_decay_time_t dt;
-	dt.u = atomic_read_zu(&arena->decay.time.u);
-	return dt.s;
+	return atomic_read_zd(&arena->decay.time);
 }
 
 static void
 arena_decay_time_write(arena_t *arena, ssize_t decay_time) {
-	arena_decay_time_t dt;
-	dt.s = decay_time;
-	atomic_write_zu(&arena->decay.time.u, dt.u);
+	atomic_write_zd(&arena->decay.time, decay_time);
 }
 
 static void