Fixed spelling -- super set -> superset.
diff --git a/docs/ref/contrib/gis/geos.txt b/docs/ref/contrib/gis/geos.txt
index 206a24c8aa834..bf8595811fef2 100644
--- a/docs/ref/contrib/gis/geos.txt
+++ b/docs/ref/contrib/gis/geos.txt
@@ -302,7 +302,7 @@ another object.
 .. attribute:: GEOSGeometry.ewkt
 
 Returns the "extended" Well-Known Text of the geometry.  This representation
-is specific to PostGIS and is a super set of the OGC WKT standard. [#fnogc]_
+is specific to PostGIS and is a superset of the OGC WKT standard. [#fnogc]_
 Essentially the SRID is prepended to the WKT representation, for example
 ``SRID=4326;POINT(5 23)``.
 
