diff --git a/yamllint/linter.py b/yamllint/linter.py
index c639dbe8..73871e58 100644
--- a/yamllint/linter.py
+++ b/yamllint/linter.py
@@ -170,7 +170,7 @@ def process_comment(self, comment):
             for problem in cache:
                 if not (disabled_for_line.is_disabled_by_directive(problem) or
                         disabled.is_disabled_by_directive(problem)):
-                    if conf.rules[problem.rule]["disable_after_first_occurence"]:
+                    if conf.rules[problem.rule].get('disable_after_first_occurence', False):
                         disabled.disable_by_force(problem)
                     yield problem