diff --git a/inst/NEWS.Rd b/inst/NEWS.Rd
index 24f4614dd2429c148a8a99c1da36cbbad193ff05..01828146cbded76139b31652c445d9b278b9bd7e 100644
--- a/inst/NEWS.Rd
+++ b/inst/NEWS.Rd
@@ -13,6 +13,7 @@
     \item additional example for readProb and writeProb.
     \item modified \code{multiDel} to not use \code{require}
     \item \code{doubleFluxDel} had a bug if \code{react1} or \code{react2} contained duplicated entries.
+    \item documentation of \code{hasEffect} in \code{optsol_genedel} is now clearer.
   }
 }
 
diff --git a/man/optsol_genedel-class.Rd b/man/optsol_genedel-class.Rd
index 0ba541582ec3d7eedf4a412597314fff72a019ba..0e71588b38c2d54d904a8f24257cd77935ffc605 100644
--- a/man/optsol_genedel-class.Rd
+++ b/man/optsol_genedel-class.Rd
@@ -42,7 +42,8 @@
     }
     \item{\code{hasEffect}:}{
       Object of class \code{"logical"} indicating whether deletion of
-      gene \code{i} has an effect or not.
+      gene \code{i} has an effect or not. This is determined on basis of the 
+      \code{gprRules} and not by optimizations.
     }
     \item{\code{chlb}:}{Object of class \code{"numeric"}
       containing the new (changed) values for the columns lower bounds.