diff --git a/spec/lib/universign/api_spec.rb b/spec/lib/universign/api_spec.rb
index 0d026642c..b87aade6d 100644
--- a/spec/lib/universign/api_spec.rb
+++ b/spec/lib/universign/api_spec.rb
@@ -4,6 +4,10 @@ describe Universign::API do
 
     let(:digest) { Digest::SHA256.hexdigest("CECI EST UN HASH") }
 
+    before do
+      stub_const("UNIVERSIGN_API_URL", "https://ws.universign.eu/tsa/post/")
+    end
+
     it { is_expected.not_to be_nil }
   end
 end