diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1f44ed59b..131c7e689 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -89,7 +89,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-          - macos-latest
+          - macos-11
+          - macos-10.15
         config:
           - { name: "cmake_gcc", cc: "gcc", cxx: "g++" }
           - { name: "cmake_clang", cc: "clang", cxx: "clang++" }
diff --git a/ChangeLog.adoc b/ChangeLog.adoc
index 0bc58e487..7b2d564df 100644
--- a/ChangeLog.adoc
+++ b/ChangeLog.adoc
@@ -40,6 +40,10 @@ Bug fixes::
   * irc: fix parsing of CAP message when there is no prefix (issue #1707)
   * irc: fix parsing of TAGMSG message when there is a colon before the channel
 
+Tests::
+
+  * core: add build on macOS 11 in CI
+
 Build::
 
   * core: add targets "changelog" and "rn" to build HTML version of ChangeLog and release notes (CMake build only)