diff --git a/src/vnet/error.h b/src/vnet/error.h
index 3feb8ff..fa13375 100644
--- a/src/vnet/error.h
+++ b/src/vnet/error.h
@@ -158,7 +158,8 @@
   _ (BUSY, -167, "Busy")                                                      \
   _ (BUG, -168, "Bug")                                                        \
   _ (FEATURE_ALREADY_DISABLED, -169, "Feature already disabled")              \
-  _ (FEATURE_ALREADY_ENABLED, -170, "Feature already enabled")
+  _ (FEATURE_ALREADY_ENABLED, -170, "Feature already enabled")                \
+  _ (INVALID_PREFIX_LENGTH, -171, "Invalid prefix length")
 
 typedef enum
 {