diff --git a/.github/matrix.py b/.github/matrix.py
index e713afc37..9c9b966f6 100755
--- a/.github/matrix.py
+++ b/.github/matrix.py
@@ -280,7 +280,7 @@ def main(ref_name):
     if "haproxy-" in ref_name:
         os = "macos-13"     # stable branch
     else:
-        os = "macos-15"     # development branch
+        os = "macos-26"     # development branch
 
     TARGET = "osx"
     for CC in ["clang"]: