diff --git a/test/activate.jl b/test/activate.jl
new file mode 100644
index 0000000..d360514
--- /dev/null
+++ b/test/activate.jl
@@ -0,0 +1,33 @@
+@testset "Loading and unloading a model" begin
+    GU = GamsUniverse()
+
+    @create_set!(GU,:i,"Test Set",begin
+        a,"elm"
+        b,"elm2"
+    end)
+    
+    alias(GU,:i,:j)
+    
+    
+    
+    @create_parameters(GU,begin
+        :p, (:i,:j), "test parm"
+    end)
+
+    deactivate(GU,:i,:a)
+    
+
+    @create_parameters(GU,begin
+        :q, (:i,:j), "test parm"
+    end)
+
+    @test GU[:p][:i,:j] == [0 0]
+    @test GU[:q][:i,:j] == [0 0]
+
+    activate(GU,:i,:a)
+    
+    
+    @test GU[:p][:i,:j] == [0 0; 0 0]
+    @test GU[:q][:i,:j] == [0 0; 0 0]
+    
+end
\ No newline at end of file
diff --git a/test/runtests.jl b/test/runtests.jl
index bc6e86e..3abacbf 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -6,7 +6,7 @@ using GamsStructure
 
     include("load_unload.jl")
 
-
+    include("activate.jl")
 
 
 end
\ No newline at end of file