diff --git a/lib/prepare_release.js b/lib/prepare_release.js
index c798c466..e0d989e8 100644
--- a/lib/prepare_release.js
+++ b/lib/prepare_release.js
@@ -37,7 +37,7 @@ export default class ReleasePreparation extends Session {
   }
 
   get branch() {
-    return this.stagingBranch;
+    return this.isSecurityRelease ? this.releaseBranch : this.stagingBranch;
   }
 
   warnForNonMergeablePR(pr) {
@@ -520,7 +520,7 @@ export default class ReleasePreparation extends Session {
     await fs.writeFile(majorChangelogPath, arr.join('\n'));
   }
 
-  async createProposalBranch(base = this.stagingBranch) {
+  async createProposalBranch(base = this.branch) {
     const { newVersion } = this;
     const proposalBranch = `v${newVersion}-proposal`;