diff --git a/resources/definitions/fdmprinter.def.json b/resources/definitions/fdmprinter.def.json
index a7853328d3..8db96bb843 100755
--- a/resources/definitions/fdmprinter.def.json
+++ b/resources/definitions/fdmprinter.def.json
@@ -1321,7 +1321,7 @@
                 "max_skin_angle_for_expansion":
                 {
                     "label": "Maximum Skin Angle for Expansion",
-                    "description": "Top and or bottom surfaces of your object with an angle larger than this setting, won't have their top/bottom skin expanded. This avoids expanding the narrow skin areas that are created when the model surface has a near vertical slope. An angle of 0° is horizontal, while an angle of 90° is vertical.",
+                    "description": "Top and/or bottom surfaces of your object with an angle larger than this setting, won't have their top/bottom skin expanded. This avoids expanding the narrow skin areas that are created when the model surface has a near vertical slope. An angle of 0° is horizontal, while an angle of 90° is vertical.",
                     "unit": "°",
                     "type": "float",
                     "minimum_value": "0",