diff --git a/include/jemalloc/internal/background_thread_structs.h b/include/jemalloc/internal/background_thread_structs.h
index c1107dfe..c02aa434 100644
--- a/include/jemalloc/internal/background_thread_structs.h
+++ b/include/jemalloc/internal/background_thread_structs.h
@@ -9,6 +9,7 @@
 
 #define BACKGROUND_THREAD_INDEFINITE_SLEEP UINT64_MAX
 #define MAX_BACKGROUND_THREAD_LIMIT MALLOCX_ARENA_LIMIT
+#define DEFAULT_NUM_BACKGROUND_THREAD 4
 
 typedef enum {
 	background_thread_stopped,
diff --git a/src/background_thread.c b/src/background_thread.c
index 24f67305..813867ef 100644
--- a/src/background_thread.c
+++ b/src/background_thread.c
@@ -13,7 +13,7 @@ JEMALLOC_DIAGNOSTIC_DISABLE_SPURIOUS
 #define BACKGROUND_THREAD_DEFAULT false
 /* Read-only after initialization. */
 bool opt_background_thread = BACKGROUND_THREAD_DEFAULT;
-size_t opt_max_background_threads = MAX_BACKGROUND_THREAD_LIMIT;
+size_t opt_max_background_threads = MAX_BACKGROUND_THREAD_LIMIT + 1;
 
 /* Used for thread creation, termination and stats. */
 malloc_mutex_t background_thread_lock;
@@ -872,9 +872,8 @@ background_thread_boot1(tsdn_t *tsdn) {
 	assert(have_background_thread);
 	assert(narenas_total_get() > 0);
 
-	if (opt_max_background_threads == MAX_BACKGROUND_THREAD_LIMIT &&
-	    ncpus < MAX_BACKGROUND_THREAD_LIMIT) {
-		opt_max_background_threads = ncpus;
+	if (opt_max_background_threads > MAX_BACKGROUND_THREAD_LIMIT) {
+		opt_max_background_threads = DEFAULT_NUM_BACKGROUND_THREAD;
 	}
 	max_background_threads = opt_max_background_threads;