diff --git a/.github/workflows/ios-ci.yml b/.github/workflows/ios-ci.yml
index 5605f43ec..531e34374 100644
--- a/.github/workflows/ios-ci.yml
+++ b/.github/workflows/ios-ci.yml
@@ -21,7 +21,7 @@ on:
 
 jobs:
   build:
-    runs-on: macos-latest
+    runs-on: macos-10.15
     env:
       BUILDTYPE: Debug
       HOMEBREW_NO_AUTO_UPDATE: 1