diff --git a/src/box/gc.c b/src/box/gc.c
index 1f8cc818d19330236b746cffe786a5de52adf6e5..9af4ef958b18b34d5a2abb270cdcdee01a3edc50 100644
--- a/src/box/gc.c
+++ b/src/box/gc.c
@@ -239,7 +239,7 @@ gc_cleanup_fiber_f(va_list ap)
 {
 	(void)ap;
 	while (!fiber_is_cancelled()) {
-		int delta = gc.cleanup_scheduled - gc.cleanup_completed;
+		int64_t delta = gc.cleanup_scheduled - gc.cleanup_completed;
 		if (delta == 0) {
 			/* No pending garbage collection. */
 			fiber_sleep(TIMEOUT_INFINITY);
@@ -278,7 +278,7 @@ gc_schedule_cleanup(void)
 static void
 gc_wait_cleanup(void)
 {
-	unsigned scheduled = gc.cleanup_scheduled;
+	int64_t scheduled = gc.cleanup_scheduled;
 	while (gc.cleanup_completed < scheduled)
 		fiber_cond_wait(&gc.cleanup_cond);
 }
diff --git a/src/box/gc.h b/src/box/gc.h
index 829aaf479a6e648bf5a594648121c6a7ea2d0fcf..2a568c5f96842cba6935d01d75f093f7e5f2020c 100644
--- a/src/box/gc.h
+++ b/src/box/gc.h
@@ -146,7 +146,7 @@ struct gc_state {
 	 * sleep until @completed reaches the value of @scheduled
 	 * taken at that moment of time.
 	 */
-	unsigned cleanup_completed, cleanup_scheduled;
+	int64_t cleanup_completed, cleanup_scheduled;
 	/**
 	 * Set if there's a fiber making a checkpoint right now.
 	 */