diff --git a/engine/src/flutter/ci/builders/mac_host_engine.json b/engine/src/flutter/ci/builders/mac_host_engine.json
index 0331885d87..97df7b9fd5 100644
--- a/engine/src/flutter/ci/builders/mac_host_engine.json
+++ b/engine/src/flutter/ci/builders/mac_host_engine.json
@@ -10,6 +10,10 @@
         "Tests to run on mac hosts should go in one of the other mac_ build ",
         "definition files."
     ],
+    "luci_flags": {
+      "delay_collect_builds": true,
+      "parallel_download_builds": true
+    },
     "builds": [
         {
             "drone_dimensions": [
diff --git a/engine/src/flutter/ci/builders/mac_ios_engine.json b/engine/src/flutter/ci/builders/mac_ios_engine.json
index 78423c2acc..08d51bfe86 100644
--- a/engine/src/flutter/ci/builders/mac_ios_engine.json
+++ b/engine/src/flutter/ci/builders/mac_ios_engine.json
@@ -7,6 +7,10 @@
         "Tests to run on mac hosts should go in one of the other mac_ build ",
         "definition files."
     ],
+    "luci_flags": {
+      "delay_collect_builds": true,
+      "parallel_download_builds": true
+    },
     "builds": [
         {
             "drone_dimensions": [