diff --git a/test/e2e/parallel/nstemplatetier_test.go b/test/e2e/parallel/nstemplatetier_test.go
index 6d6bdcef5..644e8ba7b 100644
--- a/test/e2e/parallel/nstemplatetier_test.go
+++ b/test/e2e/parallel/nstemplatetier_test.go
@@ -432,8 +432,7 @@ func TestTierTemplateRevision(t *testing.T) {
 			// when
 			// we update a parameter in the NSTemplateTier
 			// by increasing the deployment quota
-			customTier.NSTemplateTier.Spec.Parameters = []toolchainv1alpha1.Parameter{{Name: "DEPLOYMENT_QUOTA", Value: "100"}}
-			customTier = tiers.UpdateCustomNSTemplateTier(t, hostAwait, customTier)
+			customTier = tiers.UpdateCustomNSTemplateTier(t, hostAwait, customTier, tiers.WithParameter("DEPLOYMENT_QUOTA", "100"))
 			require.NoError(t, err)
 
 			// then
diff --git a/testsupport/tiers/tier_setup.go b/testsupport/tiers/tier_setup.go
index a1fe4a34a..02241063a 100644
--- a/testsupport/tiers/tier_setup.go
+++ b/testsupport/tiers/tier_setup.go
@@ -86,12 +86,28 @@ func WithParameter(name, value string) CustomNSTemplateTierModifier {
 		if tier.Spec.Parameters == nil {
 			tier.Spec.Parameters = []toolchainv1alpha1.Parameter{}
 		}
-		tier.Spec.Parameters = append(tier.Spec.Parameters,
-			toolchainv1alpha1.Parameter{
-				Name:  name,
-				Value: value,
-			},
-		)
+
+		newParams := make([]toolchainv1alpha1.Parameter, len(tier.Spec.Parameters))
+		// search for the param, in case it already exists, we need only to change its value
+		found := false
+		for _, param := range tier.Spec.Parameters {
+			if param.Name == name {
+				// if the param already exists, let's set the new value
+				param.Value = value
+				found = true
+			}
+			newParams = append(newParams, param)
+		}
+		// if it's a new parameter, let's append it to the existing ones
+		if !found {
+			newParams = append(newParams,
+				toolchainv1alpha1.Parameter{
+					Name:  name,
+					Value: value,
+				},
+			)
+		}
+		tier.Spec.Parameters = newParams
 		return nil
 	}
 }