diff --git a/.ci/ci_lib.py b/.ci/ci_lib.py
index 8193a34c..6a771662 100644
--- a/.ci/ci_lib.py
+++ b/.ci/ci_lib.py
@@ -58,6 +58,7 @@ def _have_cmd(args):
     try:
         subprocess.run(
             args, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
+            check=True,
         )
     except OSError as exc:
         if exc.errno == errno.ENOENT:
diff --git a/tests/testlib.py b/tests/testlib.py
index a0e27d95..b91739e6 100644
--- a/tests/testlib.py
+++ b/tests/testlib.py
@@ -160,6 +160,7 @@ def _have_cmd(args):
     try:
         subprocess.run(
             args, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
+            check=True,
         )
     except OSError as exc:
         if exc.errno == errno.ENOENT: