diff --git a/dexpreopt/config.go b/dexpreopt/config.go
index eefda19..609a29c 100644
--- a/dexpreopt/config.go
+++ b/dexpreopt/config.go
@@ -96,6 +96,8 @@
 	// quickly silence build errors. This flag should be used with caution and only as a temporary
 	// measure, as it masks real errors and affects performance.
 	RelaxUsesLibraryCheck bool
+
+	EnableUffdGc bool // preopt with the assumption that userfaultfd GC will be used on device.
 }
 
 var allPlatformSystemServerJarsKey = android.NewOnceKey("allPlatformSystemServerJars")
diff --git a/dexpreopt/dexpreopt.go b/dexpreopt/dexpreopt.go
index fdfd22e..e3404a5 100644
--- a/dexpreopt/dexpreopt.go
+++ b/dexpreopt/dexpreopt.go
@@ -495,6 +495,10 @@
 		cmd.FlagWithInput("--profile-file=", profile)
 	}
 
+	if global.EnableUffdGc {
+		cmd.Flag("--runtime-arg").Flag("-Xgc:CMC")
+	}
+
 	rule.Install(odexPath, odexInstallPath)
 	rule.Install(vdexPath, vdexInstallPath)
 }
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index b3faae8..3effff6 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -752,6 +752,10 @@
 		cmd.FlagWithArg("--instruction-set-features=", global.InstructionSetFeatures[arch])
 	}
 
+	if global.EnableUffdGc {
+		cmd.Flag("--runtime-arg").Flag("-Xgc:CMC")
+	}
+
 	if global.BootFlags != "" {
 		cmd.Flag(global.BootFlags)
 	}