diff --git a/src/vnet/flow/flow.c b/src/vnet/flow/flow.c
index 4d867fe..9b6a376 100644
--- a/src/vnet/flow/flow.c
+++ b/src/vnet/flow/flow.c
@@ -96,6 +96,9 @@
   uword private_data;
   int rv;
 
+  if (f == 0)
+    return VNET_FLOW_ERROR_NO_SUCH_ENTRY;
+
   if (!vnet_hw_interface_is_valid (vnm, hw_if_index))
     return VNET_FLOW_ERROR_NO_SUCH_INTERFACE;
 
@@ -137,6 +140,9 @@
   uword *p;
   int rv;
 
+  if (f == 0)
+    return VNET_FLOW_ERROR_NO_SUCH_ENTRY;
+
   if (!vnet_hw_interface_is_valid (vnm, hw_if_index))
     return VNET_FLOW_ERROR_NO_SUCH_INTERFACE;