diff --git a/include/jemalloc/internal/extent_inlines.h b/include/jemalloc/internal/extent_inlines.h
index 145fa2d6..c931fd58 100644
--- a/include/jemalloc/internal/extent_inlines.h
+++ b/include/jemalloc/internal/extent_inlines.h
@@ -264,6 +264,12 @@ extent_nfree_dec(extent_t *extent) {
 	extent->e_bits -= ((uint64_t)1U << EXTENT_BITS_NFREE_SHIFT);
 }
 
+static inline void
+extent_nfree_sub(extent_t *extent, uint64_t n) {
+	assert(extent_slab_get(extent));
+	extent->e_bits -= (n << EXTENT_BITS_NFREE_SHIFT);
+}
+
 static inline void
 extent_sn_set(extent_t *extent, size_t sn) {
 	extent->e_bits = (extent->e_bits & ~EXTENT_BITS_SN_MASK) |
diff --git a/src/arena.c b/src/arena.c
index fc2a7dff..841f2950 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -283,10 +283,10 @@ arena_slab_reg_alloc_batch(extent_t *slab, const bin_info_t *bin_info,
 		regind = bitmap_sfu(slab_data->bitmap, &bin_info->bitmap_info);
 		ret = (void *)((uintptr_t)extent_addr_get(slab) +
 		    (uintptr_t)(bin_info->reg_size * regind));
-		extent_nfree_dec(slab);
 
 		*(ptrs + i) = ret;
 	}
+	extent_nfree_sub(slab, cnt);
 }
 
 #ifndef JEMALLOC_JET