diff --git a/dev-infra/pullapprove/parse-yaml.ts b/dev-infra/pullapprove/parse-yaml.ts
index 9e63ce6a98..c0856d1763 100644
--- a/dev-infra/pullapprove/parse-yaml.ts
+++ b/dev-infra/pullapprove/parse-yaml.ts
@@ -31,5 +31,5 @@ export interface PullApproveConfig {
 }
 
 export function parsePullApproveYaml(rawYaml: string): PullApproveConfig {
-  return parseYaml(rawYaml) as PullApproveConfig;
+  return parseYaml(rawYaml, {merge: true}) as PullApproveConfig;
 }