diff --git a/performance/compare.py b/performance/compare.py
index 3af4680..dd7c3f8 100644
--- a/performance/compare.py
+++ b/performance/compare.py
@@ -28,6 +28,7 @@ def run_vcztools(command: str, dataset_name: str):
 if __name__ == "__main__":
     commands = [
         ("view", "sim_10k"),
+        ("view", "chr22"),
         ("view -s tsk_7068,tsk_8769,tsk_8820", "sim_10k"),
         (r"query -f '%CHROM %POS %REF %ALT{0}\n'", "sim_10k"),
         (r"query -f '%CHROM:%POS\n' -i 'POS=49887394 | POS=50816415'", "sim_10k"),
diff --git a/vcztools/cli.py b/vcztools/cli.py
index cfd1322..693a6c4 100644
--- a/vcztools/cli.py
+++ b/vcztools/cli.py
@@ -151,7 +151,7 @@ def view(
     include,
     exclude,
 ):
-    if output and not output.endswith(".vcf"):
+    if output and not output.endswith(".vcf") and output != "/dev/null":
         split = output.split(".")
         raise ValueError(f"Output file extension must be .vcf, got: .{split[-1]}")