diff --git a/tools/aconfig/src/commands.rs b/tools/aconfig/src/commands.rs
index 47e90ac..d04c0cf 100644
--- a/tools/aconfig/src/commands.rs
+++ b/tools/aconfig/src/commands.rs
@@ -57,6 +57,7 @@
 
 pub fn parse_flags(
     package: &str,
+    container: Option<&str>,
     declarations: Vec<Input>,
     values: Vec<Input>,
     default_permission: ProtoFlagPermission,
@@ -79,12 +80,24 @@
             package,
             flag_declarations.package()
         );
+        if let Some(c) = container {
+            ensure!(
+                c == flag_declarations.container(),
+                "failed to parse {}: expected container {}, got {}",
+                input.source,
+                c,
+                flag_declarations.container()
+            );
+        }
         for mut flag_declaration in flag_declarations.flag.into_iter() {
             crate::protos::flag_declaration::verify_fields(&flag_declaration)
                 .with_context(|| input.error_context())?;
 
             // create ParsedFlag using FlagDeclaration and default values
             let mut parsed_flag = ProtoParsedFlag::new();
+            if let Some(c) = container {
+                parsed_flag.set_container(c.to_string());
+            }
             parsed_flag.set_package(package.to_string());
             parsed_flag.set_name(flag_declaration.take_name());
             parsed_flag.set_namespace(flag_declaration.take_namespace());
@@ -262,9 +275,10 @@
         DumpFormat::Text => {
             for parsed_flag in parsed_flags.parsed_flag.into_iter() {
                 let line = format!(
-                    "{}.{}: {:?} + {:?}\n",
+                    "{}.{} [{}]: {:?} + {:?}\n",
                     parsed_flag.package(),
                     parsed_flag.name(),
+                    parsed_flag.container(),
                     parsed_flag.permission(),
                     parsed_flag.state()
                 );
@@ -276,9 +290,10 @@
                 let sources: Vec<_> =
                     parsed_flag.trace.iter().map(|tracepoint| tracepoint.source()).collect();
                 let line = format!(
-                    "{}.{}: {:?} + {:?} ({})\n",
+                    "{}.{} [{}]: {:?} + {:?} ({})\n",
                     parsed_flag.package(),
                     parsed_flag.name(),
+                    parsed_flag.container(),
                     parsed_flag.permission(),
                     parsed_flag.state(),
                     sources.join(", ")
@@ -377,6 +392,7 @@
 
         let flags_bytes = crate::commands::parse_flags(
             "com.first",
+            None,
             declaration,
             value,
             ProtoFlagPermission::READ_ONLY,
@@ -391,9 +407,72 @@
     }
 
     #[test]
+    fn test_parse_flags_package_mismatch_between_declaration_and_command_line() {
+        let first_flag = r#"
+        package: "com.declaration.package"
+        container: "first.container"
+        flag {
+            name: "first"
+            namespace: "first_ns"
+            description: "This is the description of the first flag."
+            bug: "123"
+        }
+        "#;
+        let declaration =
+            vec![Input { source: "memory".to_string(), reader: Box::new(first_flag.as_bytes()) }];
+
+        let value: Vec<Input> = vec![];
+
+        let error = crate::commands::parse_flags(
+            "com.argument.package",
+            Some("first.container"),
+            declaration,
+            value,
+            ProtoFlagPermission::READ_WRITE,
+        )
+        .unwrap_err();
+        assert_eq!(
+            format!("{:?}", error),
+            "failed to parse memory: expected package com.argument.package, got com.declaration.package"
+        );
+    }
+
+    #[test]
+    fn test_parse_flags_container_mismatch_between_declaration_and_command_line() {
+        let first_flag = r#"
+        package: "com.first"
+        container: "declaration.container"
+        flag {
+            name: "first"
+            namespace: "first_ns"
+            description: "This is the description of the first flag."
+            bug: "123"
+        }
+        "#;
+        let declaration =
+            vec![Input { source: "memory".to_string(), reader: Box::new(first_flag.as_bytes()) }];
+
+        let value: Vec<Input> = vec![];
+
+        let error = crate::commands::parse_flags(
+            "com.first",
+            Some("argument.container"),
+            declaration,
+            value,
+            ProtoFlagPermission::READ_WRITE,
+        )
+        .unwrap_err();
+        assert_eq!(
+            format!("{:?}", error),
+            "failed to parse memory: expected container argument.container, got declaration.container"
+        );
+    }
+
+    #[test]
     fn test_parse_flags_override_fixed_read_only() {
         let first_flag = r#"
         package: "com.first"
+        container: "com.first.container"
         flag {
             name: "first"
             namespace: "first_ns"
@@ -419,6 +498,7 @@
         }];
         let error = crate::commands::parse_flags(
             "com.first",
+            Some("com.first.container"),
             declaration,
             value,
             ProtoFlagPermission::READ_WRITE,
@@ -451,7 +531,9 @@
         let input = parse_test_flags_as_input();
         let bytes = dump_parsed_flags(vec![input], DumpFormat::Text).unwrap();
         let text = std::str::from_utf8(&bytes).unwrap();
-        assert!(text.contains("com.android.aconfig.test.disabled_ro: READ_ONLY + DISABLED"));
+        assert!(
+            text.contains("com.android.aconfig.test.disabled_ro [system]: READ_ONLY + DISABLED")
+        );
     }
 
     #[test]