diff --git a/tools/grammarcheckers/grammarchecker.cg3 b/tools/grammarcheckers/grammarchecker.cg3
index e422dc62a..c0cf4a525 100644
--- a/tools/grammarcheckers/grammarchecker.cg3
+++ b/tools/grammarcheckers/grammarchecker.cg3
@@ -58,7 +58,7 @@ INCLUDE STATIC liststemplates.cg3 ;
 
 BEFORE-SECTIONS
 #heuristic tags in order to correct other parts of sentence
-ADD <heur-prop> ("\\p{Lu}.*"r ?) ;
+ADD <heur-prop> ("\\p{Lu}.*"r ?) (NEGATE -1 BOS) ;
 ADD <heur-Abs-Sg> ("\\p{Lu}.*a"r ?) (-1 (/UTE\ Der/vn\ N\ Abs\ Sg/l)) ;
 #[Aqqama]: Inuit aqqinik qinnuteqaat Aqqama ilissinnut akuerisassatut ingerlateqqippara. Tunngavilersuutingineqarneri taajuutaavoq aammalu allattaasitaamut naapertuulluni.