diff --git a/.ci.yaml b/.ci.yaml
index a11e56dec89..3b35166ee93 100644
--- a/.ci.yaml
+++ b/.ci.yaml
@@ -166,7 +166,7 @@ platform_properties:
         [
           {"dependency": "apple_signing", "version": "version:to_2026"}
         ]
-      os: Mac-14|Mac-15
+      os: Mac-15.5
       device_type: none
       $flutter/osx_sdk : >-
         {
@@ -183,7 +183,7 @@ platform_properties:
         [
           {"dependency": "apple_signing", "version": "version:to_2026"}
         ]
-      os: Mac-14|Mac-15
+      os: Mac-15.5
       device_type: none
       cpu: arm64
       $flutter/osx_sdk : >-
@@ -203,7 +203,7 @@ platform_properties:
         ]
       device_type: none
       mac_model: "Macmini8,1"
-      os: Mac-14|Mac-15
+      os: Mac-15.5
       tags: >
         ["devicelab", "hostonly", "mac"]
       $flutter/osx_sdk : >-
@@ -221,7 +221,7 @@ platform_properties:
         [
           {"dependency": "apple_signing", "version": "version:to_2026"}
         ]
-      os: Mac-14|Mac-15
+      os: Mac-15.5
       device_type: none
       cpu: x86
       $flutter/osx_sdk : >-
@@ -240,7 +240,7 @@ platform_properties:
           {"dependency": "ruby", "version": "ruby_3.1-pod_1.13"},
           {"dependency": "apple_signing", "version": "version:to_2026"}
         ]
-      os: Mac-14|Mac-15
+      os: Mac-15.5
       device_type: none
       cpu: x86
       $flutter/osx_sdk : >-
@@ -256,7 +256,7 @@ platform_properties:
           {"dependency": "chrome_and_driver", "version": "version:125.0.6422.141"},
           {"dependency": "open_jdk", "version": "version:21"}
         ]
-      os: Mac-14|Mac-15
+      os: Mac-15.1|Mac-15.5|Mac-15.6
       cpu: x86
       device_type: "mokey"
 
@@ -267,7 +267,7 @@ platform_properties:
           {"dependency": "android_sdk", "version": "version:36v4"},
           {"dependency": "open_jdk", "version": "version:21"}
         ]
-      os: Mac-14|Mac-15
+      os: Mac-15.1|Mac-15.5|Mac-15.6
       cpu: arm64
       device_type: "mokey"
 
@@ -282,7 +282,7 @@ platform_properties:
           {"dependency": "ruby", "version": "ruby_3.1-pod_1.13"},
           {"dependency": "apple_signing", "version": "version:to_2026"}
         ]
-      os: Mac-14|Mac-15
+      os: Mac-15.1|Mac-15.5|Mac-15.6
       device_os: iOS-18
       $flutter/osx_sdk : >-
         {
@@ -300,7 +300,7 @@ platform_properties:
           {"dependency": "ruby", "version": "ruby_3.1-pod_1.13"},
           {"dependency": "apple_signing", "version": "version:to_2026"}
         ]
-      os: Mac-14|Mac-15
+      os: Mac-15.1|Mac-15.5|Mac-15.6
       cpu: x86
       device_os: iOS-18
       $flutter/osx_sdk : >-
@@ -319,7 +319,7 @@ platform_properties:
           {"dependency": "ruby", "version": "ruby_3.1-pod_1.13"},
           {"dependency": "apple_signing", "version": "none"}
         ]
-      os: Mac-14|Mac-15
+      os: Mac-15.1|Mac-15.5|Mac-15.6
       cpu: arm64
       device_os: iOS-18
       $flutter/osx_sdk : >-
@@ -5559,7 +5559,7 @@ targets:
       tags: >
         ["devicelab", "ios", "mac"]
       task_name: ios_debug_workflow
-      os: Mac-15
+      os: Mac-15.5
       $flutter/osx_sdk : >-
         {
           "sdk_version": "17a5295f"
@@ -5601,7 +5601,7 @@ targets:
         ["devicelab", "ios", "mac"]
       task_name: flutter_gallery__transition_perf_e2e_ios
       drone_dimensions: >
-        ["device_os=iOS-18","os=Mac-14|Mac-15", "cpu=x86"]
+        ["device_os=iOS-18","os=Mac-15.1|Mac-15.5|Mac-15.6", "cpu=x86"]
 
   - name: Mac_ios animated_blur_backdrop_filter_perf_ios__timeline_summary
     recipe: devicelab/devicelab_drone
diff --git a/engine/src/flutter/.ci.yaml b/engine/src/flutter/.ci.yaml
index e53a13c4574..06be95d65c2 100644
--- a/engine/src/flutter/.ci.yaml
+++ b/engine/src/flutter/.ci.yaml
@@ -30,7 +30,7 @@ platform_properties:
           {"dependency": "open_jdk", "version": "version:21"}
         ]
       device_type: none
-      os: Mac-14|Mac-15
+      os: Mac-15.5
       $flutter/osx_sdk : >-
         {
           "sdk_version": "16c5032a"
@@ -470,7 +470,7 @@ targets:
     # Do not remove(https://github.com/flutter/flutter/issues/144644)
     # Scheduler will fail to get the platform
     drone_dimensions:
-      - os=Mac-14|Mac-15
+      - os=Mac-15.5
 
   - name: Mac clangd
     recipe: engine_v2/builder
@@ -499,7 +499,7 @@ targets:
     # Do not remove(https://github.com/flutter/flutter/issues/144644)
     # Scheduler will fail to get the platform
     drone_dimensions:
-      - os=Mac-14|Mac-15
+      - os=Mac-15.5
       - cpu=x86
 
   - name: Mac mac_ios_engine_ddm
@@ -519,7 +519,7 @@ targets:
     # Do not remove(https://github.com/flutter/flutter/issues/144644)
     # Scheduler will fail to get the platform
     drone_dimensions:
-      - os=Mac-14|Mac-15
+      - os=Mac-15.5
       - cpu=x86
 
   - name: Linux windows_android_aot_engine
diff --git a/engine/src/flutter/ci/builders/linux_web_engine_test.json b/engine/src/flutter/ci/builders/linux_web_engine_test.json
index cc9bc812706..29bd88c2cfa 100644
--- a/engine/src/flutter/ci/builders/linux_web_engine_test.json
+++ b/engine/src/flutter/ci/builders/linux_web_engine_test.json
@@ -397,7 +397,7 @@
       "recipe": "engine_v2/tester_engine",
       "drone_dimensions": [
         "device_type=none",
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "cpu=arm64"
       ],
       "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/local_engine.json b/engine/src/flutter/ci/builders/local_engine.json
index 51ff9ac8f03..5ff009df2c5 100644
--- a/engine/src/flutter/ci/builders/local_engine.json
+++ b/engine/src/flutter/ci/builders/local_engine.json
@@ -3,7 +3,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -36,7 +36,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -70,7 +70,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -103,7 +103,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -136,7 +136,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -170,7 +170,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -206,7 +206,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -370,7 +370,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -403,7 +403,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -436,7 +436,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -520,7 +520,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -604,7 +604,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -636,7 +636,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -669,7 +669,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -702,7 +702,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -841,7 +841,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -925,7 +925,7 @@
     {
       "cas_archive": false,
       "drone_dimensions": [
-        "os=Mac-14|Mac-15",
+        "os=Mac-15.5",
         "device_type=none"
       ],
       "gclient_variables": {
@@ -1063,7 +1063,7 @@
       "name": "macos/wasm_release",
       "drone_dimensions": [
         "device_type=none",
-        "os=Mac-14|Mac-15"
+        "os=Mac-15.5"
       ],
       "gclient_variables": {
         "download_android_deps": false,
@@ -1093,7 +1093,7 @@
       "name": "macos/wasm_debug_unopt",
       "drone_dimensions": [
         "device_type=none",
-        "os=Mac-14|Mac-15"
+        "os=Mac-15.5"
       ],
       "gclient_variables": {
         "download_android_deps": false,
diff --git a/engine/src/flutter/ci/builders/mac_android_aot_engine.json b/engine/src/flutter/ci/builders/mac_android_aot_engine.json
index 57f61d4c0b1..ead4cf8b617 100644
--- a/engine/src/flutter/ci/builders/mac_android_aot_engine.json
+++ b/engine/src/flutter/ci/builders/mac_android_aot_engine.json
@@ -25,7 +25,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -83,7 +83,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -143,7 +143,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -203,7 +203,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -261,7 +261,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -321,7 +321,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=x86"
             ],
             "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_clang_tidy.json b/engine/src/flutter/ci/builders/mac_clang_tidy.json
index 9b18f6a04ca..cf497d3bc8b 100644
--- a/engine/src/flutter/ci/builders/mac_clang_tidy.json
+++ b/engine/src/flutter/ci/builders/mac_clang_tidy.json
@@ -3,7 +3,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -36,7 +36,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -74,7 +74,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -129,7 +129,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -184,7 +184,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -239,7 +239,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -294,7 +294,7 @@
             "recipe": "engine_v2/tester_engine",
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_host_engine.json b/engine/src/flutter/ci/builders/mac_host_engine.json
index 89ebd06bbd9..5ed06bb692e 100644
--- a/engine/src/flutter/ci/builders/mac_host_engine.json
+++ b/engine/src/flutter/ci/builders/mac_host_engine.json
@@ -17,7 +17,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -84,7 +84,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -140,7 +140,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -205,7 +205,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -256,7 +256,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -307,7 +307,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -370,7 +370,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -424,7 +424,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -477,7 +477,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -543,7 +543,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -600,7 +600,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -656,7 +656,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -722,7 +722,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -777,7 +777,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -832,7 +832,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -899,7 +899,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -957,7 +957,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -1014,7 +1014,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_ios_engine.json b/engine/src/flutter/ci/builders/mac_ios_engine.json
index 3e84fdc4629..934549e832b 100644
--- a/engine/src/flutter/ci/builders/mac_ios_engine.json
+++ b/engine/src/flutter/ci/builders/mac_ios_engine.json
@@ -14,7 +14,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -61,7 +61,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -110,7 +110,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -157,7 +157,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -204,7 +204,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -251,7 +251,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -300,7 +300,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -351,7 +351,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -400,7 +400,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -449,7 +449,7 @@
         {
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
diff --git a/engine/src/flutter/ci/builders/mac_unopt.json b/engine/src/flutter/ci/builders/mac_unopt.json
index 3d86f83c40f..5ee3c8503bc 100644
--- a/engine/src/flutter/ci/builders/mac_unopt.json
+++ b/engine/src/flutter/ci/builders/mac_unopt.json
@@ -4,7 +4,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -57,7 +57,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -108,7 +108,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -159,7 +159,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -216,7 +216,7 @@
             ],
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -275,7 +275,7 @@
             },
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=x86"
             ],
             "gclient_variables": {
@@ -332,7 +332,7 @@
             "cas_archive": false,
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -400,7 +400,7 @@
             },
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
@@ -468,7 +468,7 @@
             },
             "drone_dimensions": [
                 "device_type=none",
-                "os=Mac-14|Mac-15",
+                "os=Mac-15.5",
                 "cpu=arm64"
             ],
             "gclient_variables": {
diff --git a/engine/src/flutter/lib/web_ui/dev/generate_builder_json.dart b/engine/src/flutter/lib/web_ui/dev/generate_builder_json.dart
index 40a261c61cb..dbf484b96c8 100644
--- a/engine/src/flutter/lib/web_ui/dev/generate_builder_json.dart
+++ b/engine/src/flutter/lib/web_ui/dev/generate_builder_json.dart
@@ -102,7 +102,7 @@ class GenerateBuilderJsonCommand extends Command<bool> {
         packageLock,
         'Mac',
         BrowserName.safari,
-        specificOS: 'Mac-14|Mac-15',
+        specificOS: 'Mac-15.5',
         cpu: 'arm64',
       ),
     ];