diff --git a/lib/platform/github/index.js b/lib/platform/github/index.js
index 71f9db1e903b0d89a028d8cea6e81b12d3cc8988..0feb77f36df5b8335edd5c2977d3d1e8949ef0e7 100644
--- a/lib/platform/github/index.js
+++ b/lib/platform/github/index.js
@@ -328,8 +328,12 @@ async function branchExists(branchName) {
 
 async function getAllRenovateBranches(branchPrefix) {
   logger.trace('getAllRenovateBranches');
-  const allBranches = (await get(`repos/${config.repository}/git/refs/heads`))
-    .body;
+  const allBranches = (await get(
+    `repos/${config.repository}/git/refs/heads/${branchPrefix}`,
+    {
+      paginate: true,
+    }
+  )).body;
   return allBranches.reduce((arr, branch) => {
     if (branch.ref.indexOf(`refs/heads/${branchPrefix}`) === 0) {
       arr.push(branch.ref.substring('refs/heads/'.length));