diff --git a/exercises/02/vslc/src/parser.y b/exercises/02/vslc/src/parser.y
index e567c41..f72326e 100644
--- a/exercises/02/vslc/src/parser.y
+++ b/exercises/02/vslc/src/parser.y
@@ -5,6 +5,12 @@
 %token FUNC PRINT RETURN CONTINUE IF THEN ELSE WHILE DO OPENBLOCK CLOSEBLOCK
 %token VAR NUMBER IDENTIFIER STRING
 
+%left '|' '&' '^'
+%left '+' '-'
+%left '*' '/'
+%nonassoc UMINUS
+%right '~'
+
 %%
 program:
     global_list {
@@ -217,7 +223,7 @@ expression:
   | expression '/' expression {
       node_init($$ = malloc(sizeof(node_t)), EXPRESSION, strdup("/"), 2, $1, $3);
     }
-  | '-' expression {
+  | '-' expression %prec UMINUS {
       node_init($$ = malloc(sizeof(node_t)), EXPRESSION, strdup("-"), 1, $2);
     }
   | '~' expression {