diff --git a/httpbin/core.py b/httpbin/core.py
index 0e9a85d..6b0f50d 100644
--- a/httpbin/core.py
+++ b/httpbin/core.py
@@ -469,14 +469,14 @@ def drip():
     numbytes = min(int(args.get('numbytes', 10)),(10 * 1024 * 1024)) # set 10MB limit
     code = int(args.get('code', 200))
 
-    delay = float(args.get('delay', 0))
-    if delay > 0:
-        time.sleep(delay)
-
     if numbytes <= 0:
         response = Response('number of bytes must be positive', status=400)
         return response
 
+    delay = float(args.get('delay', 0))
+    if delay > 0:
+        time.sleep(delay)
+
     pause = duration / numbytes
     def generate_bytes():
         for i in xrange(numbytes):