diff --git a/src/model.jl b/src/model.jl
index 259d70c7..75b654f9 100644
--- a/src/model.jl
+++ b/src/model.jl
@@ -655,12 +655,14 @@ function constraint!(
                     ". Please choose in [ :initial, :final, :control, :state, :variable ] or check the arguments of the constraint! method."))
                 end
                 ocp.constraints[label] = (type, fun_rg, lb, ub)
-                nothing # to force to return nothing
 
             end #
         _ => throw(IncorrectArgument("Provided arguments are inconsistent."))
     end
 
+    # update constraints dimensions
+    __set_dim_constraints(ocp)
+
 end
 
 """
@@ -805,6 +807,7 @@ function remove_constraint!(ocp::OptimalControlModel, label::Symbol)
         ". Please check the list of constraints: ocp.constraints."))
     end
     delete!(ocp.constraints, label)
+    __set_dim_constraints(ocp) # update constraints dimensions
     nothing
 end
 
@@ -1006,6 +1009,12 @@ function nlp_constraints(ocp::OptimalControlModel)
 
 end
 
+#
+function __set_dim_constraints(ocp::OptimalControlModel)
+    nlp_constraints(ocp)
+    nothing
+end
+
 # getters for constraints dimensions
 dim_control_constraints(ocp::OptimalControlModel) = ocp.dim_control_constraints 
 dim_state_constraints(ocp::OptimalControlModel) = ocp.dim_state_constraints