diff --git a/spec/system_spec.rb b/spec/system_spec.rb
index f00b975..5929a9d 100644
--- a/spec/system_spec.rb
+++ b/spec/system_spec.rb
@@ -98,6 +98,8 @@
     end
 
     context "otherwise" do
+      before { expect(subject).to receive(:os).and_return(:linux) }
+
       context "when both wget and curl are installed" do
         before do
           expect(subject).to receive(:installed?).with('wget').and_return(true)