diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index d5e1cc87f5..72fd686e34 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -1487,7 +1487,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
         }
 
         if (!avctx->rc_initial_buffer_occupancy)
-            avctx->rc_initial_buffer_occupancy = avctx->rc_buffer_size * 3 / 4;
+            avctx->rc_initial_buffer_occupancy = avctx->rc_buffer_size * 3LL / 4;
 
         if (avctx->ticks_per_frame && avctx->time_base.num &&
             avctx->ticks_per_frame > INT_MAX / avctx->time_base.num) {