diff --git a/README.md b/README.md
index 90e9686f..840bb778 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ CAD program, and create G-Code for Isolation routing.
 - fixed bug in parsing Gerber regions (a point was added unnecessary)
 - renamed the menu entry Edit -> Copy as Geo to Convert Any to Geo and moved it in the Edit -> Conversion
 - created a new function named Convert Any to Gerber and installed it in Edit -> Conversion. It's doing what the name say: it will convert an Geometry or Excellon FlatCAM object to a Gerber object.
+- another fix for bug in clear geometry processing for Gerber apertures
 
 01.05.2019
 
diff --git a/camlib.py b/camlib.py
index e55dddfb..43096a52 100644
--- a/camlib.py
+++ b/camlib.py
@@ -3225,10 +3225,10 @@ class Gerber (Geometry):
                 if 'solid_geometry' in self.apertures[apid]:
                     for solid_geo in self.apertures[apid]['solid_geometry']:
                         for clear_geo in global_clear_geo:
-                            # Make sure that the solid_geo is not completely within the clear_geo otherwise we loose
+                            # Make sure that the clear_geo is within the solid_geo otherwise we loose
                             # the solid_geometry. We want for clear_geometry just to cut into solid_geometry not to
                             # delete it
-                            if not solid_geo.within(clear_geo):
+                            if clear_geo.within(solid_geo):
                                 solid_geo = solid_geo.difference(clear_geo)
                         try:
                             for poly in solid_geo: