diff --git a/src/sfnt/ttkern.c b/src/sfnt/ttkern.c
index 32c4008..455e7b5 100644
--- a/src/sfnt/ttkern.c
+++ b/src/sfnt/ttkern.c
@@ -99,7 +99,7 @@
       length   = FT_NEXT_USHORT( p );
       coverage = FT_NEXT_USHORT( p );
 
-      if ( length <= 6 )
+      if ( length <= 6 + 8 )
         break;
 
       p_next += length;