diff --git a/bin/preparser/cmdline.c b/bin/preparser/cmdline.c
index b7512b6135..6c4a7de311 100644
--- a/bin/preparser/cmdline.c
+++ b/bin/preparser/cmdline.c
@@ -180,7 +180,7 @@ opt_set_SeekPos(struct preparser_args *args, const char *arg)
         fprintf(stderr, "Error: Seek pos should be greater than 0\n");
         return false;
     }
-    args->seek.pos = VLC_THUMBNAILER_SEEK_POS;
+    args->seek.type = VLC_THUMBNAILER_SEEK_POS;
     return true;
 }
 
@@ -487,4 +487,3 @@ preparser_cmdline_Parse(int argc, char *const *argv,
 
     return 1;
 }
-
diff --git a/bin/preparser/main.c b/bin/preparser/main.c
index 1d73ecd7a4..2a9d716e63 100644
--- a/bin/preparser/main.c
+++ b/bin/preparser/main.c
@@ -316,7 +316,7 @@ preparser_args_Preparse(vlc_preparser_t *preparser,
         pp->req_msg.req.arg.seek.type = args->seek.type;
         if (args->seek.type == VLC_THUMBNAILER_SEEK_TIME) {
             pp->req_msg.req.arg.seek.time = args->seek.time;
-        } else if (args->seek.pos == VLC_THUMBNAILER_SEEK_POS) {
+        } else if (args->seek.type == VLC_THUMBNAILER_SEEK_POS) {
             pp->req_msg.req.arg.seek.pos = args->seek.pos;
         }
         pp->req_msg.req.arg.seek.speed = args->seek.speed;
@@ -337,7 +337,7 @@ preparser_args_Preparse(vlc_preparser_t *preparser,
         pp->req_msg.req.arg.seek.type = args->seek.type;
         if (args->seek.type == VLC_THUMBNAILER_SEEK_TIME) {
             pp->req_msg.req.arg.seek.time = args->seek.time;
-        } else if (args->seek.pos == VLC_THUMBNAILER_SEEK_POS) {
+        } else if (args->seek.type == VLC_THUMBNAILER_SEEK_POS) {
             pp->req_msg.req.arg.seek.pos = args->seek.pos;
         }
         pp->req_msg.req.arg.seek.speed = args->seek.speed;