diff --git a/cmd/arcstat/arcstat.py b/cmd/arcstat/arcstat.py
index d969da8d4..aa54ee87a 100755
--- a/cmd/arcstat/arcstat.py
+++ b/cmd/arcstat/arcstat.py
@@ -219,6 +219,7 @@ def print_values():
             sep
         ))
     sys.stdout.write("\n")
+    sys.stdout.flush()
 
 
 def print_header():