diff --git a/libavcodec/libvpxenc.c b/libavcodec/libvpxenc.c
index d0bd1e997a..09f7a88452 100644
--- a/libavcodec/libvpxenc.c
+++ b/libavcodec/libvpxenc.c
@@ -493,7 +493,7 @@ static av_cold int vpx_init(AVCodecContext *avctx,
     enccfg.g_h            = avctx->height;
     enccfg.g_timebase.num = avctx->time_base.num;
     enccfg.g_timebase.den = avctx->time_base.den;
-    enccfg.g_threads      = avctx->thread_count;
+    enccfg.g_threads      = avctx->thread_count ? avctx->thread_count : av_cpu_count();
     enccfg.g_lag_in_frames= ctx->lag_in_frames;
 
     if (avctx->flags & AV_CODEC_FLAG_PASS1)