diff --git a/infra/config/global/generated/cr-buildbucket.cfg b/infra/config/global/generated/cr-buildbucket.cfg
index 0c2dfe8..b11c10e 100644
--- a/infra/config/global/generated/cr-buildbucket.cfg
+++ b/infra/config/global/generated/cr-buildbucket.cfg
@@ -30,6 +30,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "linux-clang-dbg-x86"
@@ -51,6 +55,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "linux-clang-rel-x64"
@@ -72,6 +80,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "linux-clang-rel-x86"
@@ -93,12 +105,16 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "mac-dbg"
       swarming_host: "chromium-swarm.appspot.com"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Mac-11"
+      dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.flex.ci"
       recipe {
         name: "tint"
@@ -118,12 +134,16 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "mac-rel"
       swarming_host: "chromium-swarm.appspot.com"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Mac-11"
+      dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.flex.ci"
       recipe {
         name: "tint"
@@ -143,6 +163,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-clang-dbg-x64"
@@ -168,6 +192,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-clang-dbg-x86"
@@ -193,6 +221,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-clang-rel-x64"
@@ -218,6 +250,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-clang-rel-x86"
@@ -243,6 +279,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-msvc-dbg-x64"
@@ -263,6 +303,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-msvc-rel-x64"
@@ -283,6 +327,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
   }
 }
@@ -321,6 +369,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "linux-clang-dbg-x86"
@@ -343,6 +395,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "linux-clang-rel-x64"
@@ -365,6 +421,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "linux-clang-rel-x86"
@@ -387,12 +447,16 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "mac-dbg"
       swarming_host: "chromium-swarm.appspot.com"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Mac-11"
+      dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.flex.try"
       recipe {
         name: "tint"
@@ -413,12 +477,16 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "mac-rel"
       swarming_host: "chromium-swarm.appspot.com"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Mac-11"
+      dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.flex.try"
       recipe {
         name: "tint"
@@ -439,6 +507,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "presubmit"
@@ -459,6 +531,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-clang-dbg-x64"
@@ -485,6 +561,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-clang-dbg-x86"
@@ -511,6 +591,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-clang-rel-x64"
@@ -537,6 +621,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-clang-rel-x86"
@@ -563,6 +651,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-msvc-dbg-x64"
@@ -584,6 +676,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
     builders {
       name: "win-msvc-rel-x64"
@@ -605,6 +701,10 @@
         key: "luci.recipes.use_python3"
         value: 100
       }
+      experiments {
+        key: "luci.use_realms"
+        value: 100
+      }
     }
   }
 }
diff --git a/infra/config/global/generated/project.cfg b/infra/config/global/generated/project.cfg
index 182dc1e..cfaeb59 100644
--- a/infra/config/global/generated/project.cfg
+++ b/infra/config/global/generated/project.cfg
@@ -7,7 +7,7 @@
 name: "tint"
 access: "group:all"
 lucicfg {
-  version: "1.30.4"
+  version: "1.30.1"
   package_dir: ".."
   config_dir: "generated"
   entry_point: "main.star"
diff --git a/infra/config/global/main.star b/infra/config/global/main.star
index b5157b3..ddf3bdc 100755
--- a/infra/config/global/main.star
+++ b/infra/config/global/main.star
@@ -8,7 +8,10 @@
 main.star: lucicfg configuration for Tint's standalone builers.
 """
 
+# Enable realms experiment.
+lucicfg.enable_experiment("crbug.com/1085650")
 luci.builder.defaults.experiments.set({
+    "luci.use_realms": 100,
     "luci.recipes.use_python3": 100,
 })
 
@@ -95,7 +98,7 @@
 
 os = struct(
     LINUX = os_enum("Ubuntu-18.04", os_category.LINUX, "linux"),
-    MAC = os_enum("Mac-11", os_category.MAC, "mac"),
+    MAC = os_enum("Mac-10.15", os_category.MAC, "mac"),
     WINDOWS = os_enum("Windows-10", os_category.WINDOWS, "win"),
     UNKNOWN = os_enum("Unknown", os_category.UNKNOWN, "unknown"),
 )