diff --git a/.github/workflows/autobuild.yml b/.github/workflows/autobuild.yml
index 7e64c16342..b4e61199ad 100644
--- a/.github/workflows/autobuild.yml
+++ b/.github/workflows/autobuild.yml
@@ -226,37 +226,35 @@ jobs:
 
           - config_name:            MacOS (artifacts)
             target_os:              macos
-            building_on_os:         macos-14
+            building_on_os:         macos-15
             base_command:           QT_VERSION=6.9.1 SIGN_IF_POSSIBLE=1 TARGET_ARCHS="x86_64 arm64" ./.github/autobuild/mac.sh
             # Disable CodeQL on mac as it interferes with signing the binaries (signing hangs, see #2563 and #2564)
             run_codeql:             false
-            # Latest Xcode which runs on macos-14:
-            xcode_version:          15.4.0
+            xcode_version:          16.3.0
             is_main_build_target:   true
 
           # Reminder: If Legacy is removed, be sure to add a dedicated job for CodeQL again.
           - config_name:            MacOS Legacy (artifacts+CodeQL)
             target_os:              macos
-            building_on_os:         macos-13
+            building_on_os:         macos-15-intel
             base_command:           QT_VERSION=5.15.2 SIGN_IF_POSSIBLE=0 ARTIFACT_SUFFIX=_legacy ./.github/autobuild/mac.sh
             # Enable CodeQL on mac legacy as this version does not get signed
             run_codeql:             true
-            # For Qt5 on Mac, we need to use an unsupported SDK version as macOS 13 doesn't
-            # support Xcode 12.1 which still ships SDK 10.15.
+            # macos-15-intel ships with Xcode 16.x; while Qt5 is older, Xcode 16 still supports building it
             # https://developer.apple.com/support/xcode/
             # https://xcodereleases.com/
-            xcode_version:          14.2.0
+            xcode_version:          16.3.0
             is_main_build_target:   true
 
           - config_name:            iOS (artifacts)
             target_os:              ios
-            building_on_os:         macos-14
+            building_on_os:         macos-15
             base_command:           QT_VERSION=6.7.3 ./.github/autobuild/ios.sh
             # Build failed with CodeQL enabled when last tested 03/2022 (#2490).
             # There are no hints that iOS is supposed to be supported by CodeQL.
             # Therefore, disable it:
             run_codeql:             false
-            xcode_version:          15.4.0
+            xcode_version:          16.3.0
 
           - config_name:            Windows (artifact+codeQL)
             target_os:              windows
diff --git a/Jamulus.pro b/Jamulus.pro
index afa1bde3f4..9f052a4303 100644
--- a/Jamulus.pro
+++ b/Jamulus.pro
@@ -173,6 +173,17 @@ win32 {
     }
 
 } else:macx {
+    # Set minimum macOS deployment target
+    # For Qt 5: Support back to macOS 10.13 (High Sierra) for legacy builds on Intel
+    # For Qt 6: Support macOS 11 (Big Sur) and later for universal binaries
+    lessThan(QT_MAJOR_VERSION, 6) {
+        QMAKE_MACOSX_DEPLOYMENT_TARGET = 10.13
+        message(Qt5 build: Setting macOS deployment target to 10.13)
+    } else {
+        QMAKE_MACOSX_DEPLOYMENT_TARGET = 11.0
+        message(Qt6 build: Setting macOS deployment target to 11.0)
+    }
+
     contains(CONFIG, "server_bundle") {
         message(The generated application bundle will run a server instance.)