diff --git a/modules/video_chroma/swscale.c b/modules/video_chroma/swscale.c
index d88094bb0e..3570510b07 100644
--- a/modules/video_chroma/swscale.c
+++ b/modules/video_chroma/swscale.c
@@ -372,7 +372,9 @@ static int Init( filter_t *p_filter )
     ScalerConfiguration cfg;
     if( GetParameters( &cfg, p_fmti, p_fmto, p_sys->i_sws_flags ) )
     {
-        msg_Err( p_filter, "format not supported" );
+        msg_Err( p_filter, "format not supported '%4.4s' %ux%u -> '%4.4s' %ux%u",
+                 (const char *)&p_fmti->i_chroma, p_fmti->i_visible_width, p_fmti->i_visible_height,
+                 (const char *)&p_fmto->i_chroma, p_fmto->i_visible_width, p_fmto->i_visible_height );
         return VLC_EGENERIC;
     }
     if( p_fmti->i_visible_width == 0 || p_fmti->i_visible_height == 0 ||