diff --git a/argos/commands.py b/argos/commands.py
index 23ae9f1..63b1bd9 100644
--- a/argos/commands.py
+++ b/argos/commands.py
@@ -92,8 +92,19 @@ def validate_max_lock_seconds(ctx, param, value):
     return value
 
 
+def validate_max_results(ctx, param, value):
+    if value <= 0:
+        raise click.BadParameter("Should be a positive integer")
+    return value
+
+
 @server.command()
-@click.option("--max-results", default=100, help="Number of results per task to keep")
+@click.option(
+    "--max-results",
+    default=100,
+    help="Number of results per task to keep",
+    callback=validate_max_results,
+)
 @click.option(
     "--max-lock-seconds",
     default=100,