diff --git a/lib/platform/github/index.js b/lib/platform/github/index.js
index 1cdb58e30e35702830db3b88bda4ab13ba355185..dc35221f374a39b6a3c06fa93204ead9141be8d2 100644
--- a/lib/platform/github/index.js
+++ b/lib/platform/github/index.js
@@ -404,30 +404,34 @@ async function branchExists(branchName) {
 
 async function getAllRenovateBranches(branchPrefix) {
   logger.trace('getAllRenovateBranches');
-  const allBranches = (await get(
-    `repos/${config.repository}/git/refs/heads/${branchPrefix}`,
-    {
-      paginate: true,
-    }
-  )).body;
-  return allBranches.reduce((arr, branch) => {
-    if (branch.ref.startsWith(`refs/heads/${branchPrefix}`)) {
-      arr.push(branch.ref.substring('refs/heads/'.length));
-    }
-    if (
-      branchPrefix.endsWith('/') &&
-      branch.ref === `refs/heads/${branchPrefix.slice(0, -1)}`
-    ) {
-      logger.warn(
-        `Pruning branch "${branchPrefix.slice(
-          0,
-          -1
-        )}" so that it does not block PRs`
-      );
-      arr.push(branch.ref.substring('refs/heads/'.length));
-    }
-    return arr;
-  }, []);
+  try {
+    const allBranches = (await get(
+      `repos/${config.repository}/git/refs/heads/${branchPrefix}`,
+      {
+        paginate: true,
+      }
+    )).body;
+    return allBranches.reduce((arr, branch) => {
+      if (branch.ref.startsWith(`refs/heads/${branchPrefix}`)) {
+        arr.push(branch.ref.substring('refs/heads/'.length));
+      }
+      if (
+        branchPrefix.endsWith('/') &&
+        branch.ref === `refs/heads/${branchPrefix.slice(0, -1)}`
+      ) {
+        logger.warn(
+          `Pruning branch "${branchPrefix.slice(
+            0,
+            -1
+          )}" so that it does not block PRs`
+        );
+        arr.push(branch.ref.substring('refs/heads/'.length));
+      }
+      return arr;
+    }, []);
+  } catch (err) /* istanbul ignore next */ {
+    return [];
+  }
 }
 
 async function isBranchStale(branchName) {