diff --git a/src/spanish/DictSpa.gf b/src/spanish/DictSpa.gf
index c1c44db22..54f8f6a03 100644
--- a/src/spanish/DictSpa.gf
+++ b/src/spanish/DictSpa.gf
@@ -20577,7 +20577,7 @@ lin grasoso_A = mkA "grasoso" ;
 lin gratificación_N = mkN "gratificación" ;
 lin gratificante_A = mkA "gratificante" ;
 lin gratificar_V = mkV "gratificar" ;
-lin gratis_A = mkA "gratis" ;
+lin gratis_A = invarA "gratis" ;
 lin gratis_Adv = mkAdv "gratis" ;
 lin gratitud_N = mkN "gratitud" ;
 lin grato_A = mkA "grato" ;