diff --git a/tests/main.fmf b/tests/main.fmf
index 68cc734..a15de48 100644
--- a/tests/main.fmf
+++ b/tests/main.fmf
@@ -32,3 +32,9 @@ require:
         pipenv --three
         pipenv run python -c "import os; assert os.environ['HELLO'] == 'WORLD'"
         cd ..
+
+# Check that there are no warnings in the output
+/warning:
+    test: |
+        set -eux
+        ! pipenv --version 2>&1 | grep Warning