diff --git a/gfx/gfx_thumbnail.c b/gfx/gfx_thumbnail.c
index 5e0b6002e0..20b6b14012 100644
--- a/gfx/gfx_thumbnail.c
+++ b/gfx/gfx_thumbnail.c
@@ -803,8 +803,9 @@ void gfx_thumbnail_get_draw_dimensions(
    display_aspect   = (float)width            / (float)height;
    thumbnail_aspect = (float)thumbnail->width / (float)thumbnail->height;
    core_aspect      = ((thumbnail->flags & GFX_THUMB_FLAG_CORE_ASPECT) 
-         && video_st)
-         ? video_st->av_info.geometry.aspect_ratio : thumbnail_aspect;
+         && video_st && video_st->av_info.geometry.aspect_ratio > 0)
+               ? video_st->av_info.geometry.aspect_ratio
+               : thumbnail_aspect;
 
    if (thumbnail_aspect > display_aspect)
    {
diff --git a/menu/drivers/rgui.c b/menu/drivers/rgui.c
index 9fa77d8d98..7f2521725a 100644
--- a/menu/drivers/rgui.c
+++ b/menu/drivers/rgui.c
@@ -2364,8 +2364,10 @@ static bool rgui_downscale_thumbnail(
    /* Determine output dimensions */
    float display_aspect_ratio    = (float)max_width / (float)max_height;
    float         aspect_ratio    = (float)image_src->width / (float)image_src->height;
-   float core_aspect             = (thumbnail_core_aspect && video_st)
-         ? video_st->av_info.geometry.aspect_ratio : aspect_ratio;
+   float core_aspect             = (thumbnail_core_aspect
+         && video_st && video_st->av_info.geometry.aspect_ratio > 0)
+               ? video_st->av_info.geometry.aspect_ratio
+               : aspect_ratio;
 
    if (aspect_ratio > display_aspect_ratio)
    {