diff --git a/virtualizationmanager/src/aidl.rs b/virtualizationmanager/src/aidl.rs
index 671a012..7d406d9 100644
--- a/virtualizationmanager/src/aidl.rs
+++ b/virtualizationmanager/src/aidl.rs
@@ -596,7 +596,12 @@
             params: config.params.to_owned(),
             protected: *is_protected,
             debug_config,
-            memory_mib: config.memoryMib.try_into().ok().and_then(NonZeroU32::new),
+            memory_mib: config
+                .memoryMib
+                .try_into()
+                .ok()
+                .and_then(NonZeroU32::new)
+                .unwrap_or(NonZeroU32::new(256).unwrap()),
             cpus,
             host_cpu_topology,
             console_out_fd,
diff --git a/virtualizationmanager/src/crosvm.rs b/virtualizationmanager/src/crosvm.rs
index ca938f8..23018d4 100644
--- a/virtualizationmanager/src/crosvm.rs
+++ b/virtualizationmanager/src/crosvm.rs
@@ -114,7 +114,7 @@
     pub params: Option<String>,
     pub protected: bool,
     pub debug_config: DebugConfig,
-    pub memory_mib: Option<NonZeroU32>,
+    pub memory_mib: NonZeroU32,
     pub cpus: Option<NonZeroU32>,
     pub host_cpu_topology: bool,
     pub console_out_fd: Option<File>,
@@ -942,7 +942,7 @@
         command.arg("--swiotlb").arg(swiotlb_size_mib.to_string());
 
         // b/346770542 for consistent "usable" memory across protected and non-protected VMs.
-        memory_mib = memory_mib.map(|m| m.saturating_add(swiotlb_size_mib));
+        memory_mib = memory_mib.saturating_add(swiotlb_size_mib);
 
         // Workaround to keep crash_dump from trying to read protected guest memory.
         // Context in b/238324526.
@@ -965,9 +965,7 @@
         command.arg("--params").arg("console=hvc0");
     }
 
-    if let Some(memory_mib) = memory_mib {
-        command.arg("--mem").arg(memory_mib.to_string());
-    }
+    command.arg("--mem").arg(memory_mib.to_string());
 
     if let Some(cpus) = config.cpus {
         command.arg("--cpus").arg(cpus.to_string());