diff --git a/authfs/tests/java/src/com/android/fs/AuthFsHostTest.java b/authfs/tests/java/src/com/android/fs/AuthFsHostTest.java
index 1b4fa4a..2c13ecb 100644
--- a/authfs/tests/java/src/com/android/fs/AuthFsHostTest.java
+++ b/authfs/tests/java/src/com/android/fs/AuthFsHostTest.java
@@ -108,7 +108,8 @@
                         apkName,
                         packageName,
                         configPath,
-                        /* debug */ false);
+                        /* debug */ false,
+                        /* use default memoryMib */ 0);
         adbConnectToMicrodroid(androidDevice, sCid);
 
         // Root because authfs (started from shell in this test) currently require root to open
diff --git a/compos/tests/java/android/compos/test/ComposKeyTestCase.java b/compos/tests/java/android/compos/test/ComposKeyTestCase.java
index 00b002f..d9f7065 100644
--- a/compos/tests/java/android/compos/test/ComposKeyTestCase.java
+++ b/compos/tests/java/android/compos/test/ComposKeyTestCase.java
@@ -159,7 +159,8 @@
                         apkName,
                         packageName,
                         "assets/vm_test_config.json",
-                        /* debug */ false);
+                        /* debug */ false,
+                        /* use default memoryMib */ 0);
         adbConnectToMicrodroid(getDevice(), mCid);
     }
 
diff --git a/compos/tests/java/android/compos/test/ComposTestCase.java b/compos/tests/java/android/compos/test/ComposTestCase.java
index 42a323f..40f95c3 100644
--- a/compos/tests/java/android/compos/test/ComposTestCase.java
+++ b/compos/tests/java/android/compos/test/ComposTestCase.java
@@ -150,7 +150,8 @@
                         apkName,
                         packageName,
                         "assets/vm_test_config.json",
-                        /* debug */ false);
+                        /* debug */ false,
+                        /* Use default memory */ 0);
         adbConnectToMicrodroid(getDevice(), mCid);
     }
 
diff --git a/tests/hostside/helper/java/android/virt/test/VirtualizationTestCaseBase.java b/tests/hostside/helper/java/android/virt/test/VirtualizationTestCaseBase.java
index 4c8f5eb..24a955b 100644
--- a/tests/hostside/helper/java/android/virt/test/VirtualizationTestCaseBase.java
+++ b/tests/hostside/helper/java/android/virt/test/VirtualizationTestCaseBase.java
@@ -167,7 +167,8 @@
             String apkName,
             String packageName,
             String configPath,
-            boolean debug)
+            boolean debug,
+            int memoryMib)
             throws DeviceNotAvailableException {
         CommandRunner android = new CommandRunner(androidDevice);
 
@@ -198,6 +199,7 @@
                         "run-app",
                         "--daemonize",
                         "--log " + logPath,
+                        "--mem " + memoryMib,
                         debugFlag,
                         apkPath,
                         outApkIdsigPath,
diff --git a/tests/hostside/java/android/virt/test/MicrodroidTestCase.java b/tests/hostside/java/android/virt/test/MicrodroidTestCase.java
index a7b855a..6548428 100644
--- a/tests/hostside/java/android/virt/test/MicrodroidTestCase.java
+++ b/tests/hostside/java/android/virt/test/MicrodroidTestCase.java
@@ -18,7 +18,10 @@
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
+import com.android.tradefed.device.DeviceNotAvailableException;
 import com.android.tradefed.testtype.DeviceJUnit4ClassRunner;
 
 import org.junit.After;
@@ -31,6 +34,22 @@
     private static final String APK_NAME = "MicrodroidTestApp.apk";
     private static final String PACKAGE_NAME = "com.android.microdroid.test";
 
+    private static final int MIN_MEM_ARM64 = 125;
+    private static final int MIN_MEM_X86_64 = 270;
+
+    private int minMemorySize() throws DeviceNotAvailableException {
+        CommandRunner android = new CommandRunner(getDevice());
+        String abi = android.run("getprop", "ro.product.cpu.abi");
+        assertTrue(abi != null && !abi.isEmpty());
+        if (abi.startsWith("arm64")) {
+            return MIN_MEM_ARM64;
+        } else if (abi.startsWith("x86_64")) {
+            return MIN_MEM_X86_64;
+        }
+        fail("Unsupported ABI: " + abi);
+        return 0;
+    }
+
     @Test
     public void testMicrodroidBoots() throws Exception {
         final String configPath = "assets/vm_config.json"; // path inside the APK
@@ -41,7 +60,8 @@
                         APK_NAME,
                         PACKAGE_NAME,
                         configPath,
-                        /* debug */ false);
+                        /* debug */ false,
+                        minMemorySize());
         adbConnectToMicrodroid(getDevice(), cid);
 
         // Wait until logd-init starts. The service is one of the last services that are started in
@@ -89,7 +109,14 @@
         final String configPath = "assets/vm_config.json"; // path inside the APK
         final boolean debug = true;
         final String cid =
-                startMicrodroid(getDevice(), getBuild(), APK_NAME, PACKAGE_NAME, configPath, debug);
+                startMicrodroid(
+                        getDevice(),
+                        getBuild(),
+                        APK_NAME,
+                        PACKAGE_NAME,
+                        configPath,
+                        debug,
+                        minMemorySize());
         adbConnectToMicrodroid(getDevice(), cid);
 
         assertThat(runOnMicrodroid("getenforce"), is("Permissive"));
diff --git a/vm/src/main.rs b/vm/src/main.rs
index fe47d2c..062773b 100644
--- a/vm/src/main.rs
+++ b/vm/src/main.rs
@@ -62,6 +62,11 @@
         /// Whether to run VM in debug mode.
         #[structopt(short, long)]
         debug: bool,
+
+        /// Memory size (in MiB) of the VM. If unspecified, defaults to the value of `memory_mib`
+        /// in the VM config file.
+        #[structopt(short, long)]
+        mem: Option<u32>,
     },
     /// Run a virtual machine
     Run {
@@ -118,7 +123,7 @@
         .context("Failed to find VirtualizationService")?;
 
     match opt {
-        Opt::RunApp { apk, idsig, instance, config_path, daemonize, log, debug } => {
+        Opt::RunApp { apk, idsig, instance, config_path, daemonize, log, debug, mem } => {
             command_run_app(
                 service,
                 &apk,
@@ -128,10 +133,11 @@
                 daemonize,
                 log.as_deref(),
                 debug,
+                mem,
             )
         }
         Opt::Run { config, daemonize, log } => {
-            command_run(service, &config, daemonize, log.as_deref())
+            command_run(service, &config, daemonize, log.as_deref(), /* mem */ None)
         }
         Opt::Stop { cid } => command_stop(service, cid),
         Opt::List => command_list(service),
diff --git a/vm/src/run.rs b/vm/src/run.rs
index 0d34a97..42da6a3 100644
--- a/vm/src/run.rs
+++ b/vm/src/run.rs
@@ -49,6 +49,7 @@
     daemonize: bool,
     log_path: Option<&Path>,
     debug: bool,
+    mem: Option<u32>,
 ) -> Result<(), Error> {
     let apk_file = File::open(apk).context("Failed to open APK file")?;
     let idsig_file = File::create(idsig).context("Failed to create idsig file")?;
@@ -76,8 +77,7 @@
         instanceImage: open_parcel_file(instance, true /* writable */)?.into(),
         configPath: config_path.to_owned(),
         debug,
-        // Use the default.
-        memoryMib: 0,
+        memoryMib: mem.unwrap_or(0) as i32, // 0 means use the VM default
     });
     run(service, &config, &format!("{:?}!{:?}", apk, config_path), daemonize, log_path)
 }
@@ -88,10 +88,14 @@
     config_path: &Path,
     daemonize: bool,
     log_path: Option<&Path>,
+    mem: Option<u32>,
 ) -> Result<(), Error> {
     let config_file = File::open(config_path).context("Failed to open config file")?;
-    let config =
+    let mut config =
         VmConfig::load(&config_file).context("Failed to parse config file")?.to_parcelable()?;
+    if let Some(mem) = mem {
+        config.memoryMib = mem as i32;
+    }
     run(
         service,
         &VirtualMachineConfig::RawConfig(config),