diff --git a/avconv_opt.c b/avconv_opt.c
index da8c6e75747602594b4906e014179b7f8bfdf88e..d62d11f5e6592efa0dca2e66ae228ecbc16fc4bc 100644
--- a/avconv_opt.c
+++ b/avconv_opt.c
@@ -528,6 +528,7 @@ static void add_input_streams(OptionsContext *o, AVFormatContext *ic)
                 if (!ist->hwaccel_device)
                     exit_program(1);
             }
+            ist->hwaccel_pix_fmt = AV_PIX_FMT_NONE;
 
             break;
         case AVMEDIA_TYPE_AUDIO: