diff --git a/src/arena.c b/src/arena.c
index 55651402..86acc34c 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -1375,6 +1375,7 @@ arena_ptr_array_flush_impl_large(tsdn_t *tsdn, szind_t binind,
 		edata_t *edata = item_edata[0].edata;
 		unsigned cur_arena_ind = edata_arena_ind_get(edata);
 		arena_t *cur_arena = arena_get(tsdn, cur_arena_ind, false);
+		assert(cur_arena != NULL);
 
 		if (!arena_is_auto(cur_arena)) {
 			malloc_mutex_lock(tsdn, &cur_arena->large_mtx);
@@ -1464,7 +1465,7 @@ arena_ptr_array_flush_impl(tsd_t *tsd, szind_t binind,
 	 * Checks for sized deallocation bugs, failing early rather than
 	 * corrupting metadata.
 	 */
-	size_t szind_sum = binind * nflush;
+	size_t szind_sum = (size_t)binind * nflush;
 	emap_edata_lookup_batch(tsd, &arena_emap_global, nflush,
 	    &arena_ptr_array_flush_ptr_getter, (void *)arr,
 	    &arena_ptr_array_flush_metadata_visitor, (void *)&szind_sum,
diff --git a/src/arenas_management.c b/src/arenas_management.c
index 394303a3..eb477754 100644
--- a/src/arenas_management.c
+++ b/src/arenas_management.c
@@ -166,6 +166,7 @@ arena_init(tsdn_t *tsdn, unsigned ind, const arena_config_t *config) {
 static void
 arena_bind(tsd_t *tsd, unsigned ind, bool internal) {
 	arena_t *arena = arena_get(tsd_tsdn(tsd), ind, false);
+	assert(arena != NULL);
 	arena_nthreads_inc(arena, internal);
 
 	if (internal) {
diff --git a/src/jemalloc_init.c b/src/jemalloc_init.c
index 34cfdcf5..f9ada6f8 100644
--- a/src/jemalloc_init.c
+++ b/src/jemalloc_init.c
@@ -642,6 +642,7 @@ malloc_init_hard(void) {
 		 * need it to set correct value for deferral_allowed.
 		 */
 		arena_t         *a0 = arena_get(tsd_tsdn(tsd), 0, false);
+		assert(a0 != NULL);
 		hpa_shard_opts_t hpa_shard_opts = opt_hpa_opts;
 		hpa_shard_opts.deferral_allowed = background_thread_enabled();
 		if (pa_shard_enable_hpa(tsd_tsdn(tsd), &a0->pa_shard,