diff --git a/src/GCLParser/Parser.y b/src/GCLParser/Parser.y
index 807fa454851c3f8fa09ebd9e4d4023544580e137..d8894408db40f03cd994888d99fbd118f5c28f55 100644
--- a/src/GCLParser/Parser.y
+++ b/src/GCLParser/Parser.y
@@ -71,6 +71,7 @@ import Debug.Trace
 
 %left implication
 %left or and 
+%left neg
 
 %nonassoc alias equal
 %nonassoc lessthan lessthanequal greaterthan greaterthanequal