diff --git a/tools/net/ynl/lib/nlspec.py b/tools/net/ynl/lib/nlspec.py
index 960a356e8225e63360a820b6e9f7230e2986e3e0..e01a72d06638499a8d2317223b655f154f629482 100644
--- a/tools/net/ynl/lib/nlspec.py
+++ b/tools/net/ynl/lib/nlspec.py
@@ -387,7 +387,8 @@ class SpecFamily(SpecElement):
     def resolve(self):
         self.resolve_up(super())
 
-        for elem in self.yaml['definitions']:
+        definitions = self.yaml.get('definitions', [])
+        for elem in definitions:
             if elem['type'] == 'enum' or elem['type'] == 'flags':
                 self.consts[elem['name']] = self.new_enum(elem)
             else: