diff --git a/pytest.ini b/pytest.ini
index f99e183747..5d6d3d52bb 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -4,8 +4,8 @@ addopts =
     -rfEX
     # Make tracebacks shorter
     --tb=native
-    # enable all warnings
-    -Wd
+    # turn warnings into errors
+    -Werror
 markers =
     conda: conda required to run this test (deselect with '-m \"not conda\"')
 testpaths =