diff --git a/doc/src/fix_gcmc.rst b/doc/src/fix_gcmc.rst
index 0bb59d3afc..9f64be8699 100644
--- a/doc/src/fix_gcmc.rst
+++ b/doc/src/fix_gcmc.rst
@@ -51,6 +51,8 @@ Syntax
        *intra_energy* value = intramolecular energy (energy units)
        *tfac_insert* value = scale up/down temperature of inserted atoms (unitless)
        *overlap_cutoff* value = maximum pair distance for overlap rejection (distance units)
+       *max* value = Maximum number of molecules allowed in the system
+       *min* value = Minimum number of molecules allowed in the system
 
 
 
@@ -385,6 +387,12 @@ assigning an infinite positive energy to all new configurations that
 place any pair of atoms closer than the specified overlap cutoff
 distance.
 
+The *max* and *min* keywords allow for the restriction of the number
+of atoms in the simulation. They automatically reject all insertion 
+or deletion moves that would take the system beyond the set boundaries.
+Should the system already be beyond the boundary, only moves that bring 
+the system closer to the bounds may be accepted.
+
 The *group* keyword adds all inserted atoms to the
 :doc:`group <group>` of the group-ID value. The *grouptype* keyword
 adds all inserted atoms of the specified type to the