diff --git a/meta/lib/oeqa/sdk/cases/rust.py b/meta/lib/oeqa/sdk/cases/rust.py
index 4b115bebf5..831994c14a 100644
--- a/meta/lib/oeqa/sdk/cases/rust.py
+++ b/meta/lib/oeqa/sdk/cases/rust.py
@@ -7,6 +7,7 @@
 import os
 import shutil
 import unittest
+import json
 
 from oeqa.sdk.case import OESDKTestCase
 
@@ -33,6 +34,39 @@ class RustCompileTest(OESDKTestCase):
     def test_cargo_build(self):
         self._run('cd %s/hello; cargo add zstd' % (self.tc.sdk_dir))
         self._run('cd %s/hello; cargo build' % self.tc.sdk_dir)
+    def test_check_cargo_build_default_target(self):
+        result_env = self._run("echo $RUST_TARGET_SYS_VALUE")
+        rust_target_sys = result_env.strip()
+        result = self._run(
+            "cd %s/hello; cargo build --message-format=json"
+            % self.tc.sdk_dir
+        )
+
+        executable_path = None
+        for line in result.splitlines():
+            try:
+                msg = json.loads(line)
+            except json.JSONDecodeError:
+                continue
+
+            # Cargo emits multiple JSON messages; we want the executable
+            if isinstance(msg, dict) and msg.get("executable"):
+                executable_path = msg["executable"]
+
+        self.assertIsNotNone(
+            executable_path,
+            "No executable found in cargo JSON output"
+        )
+
+        parts = executable_path.split(os.sep)
+        target_index = parts.index("target")
+        target_triple = parts[target_index + 1]
+
+        self.assertEqual(
+            rust_target_sys,
+            target_triple,
+            f"Target triple mismatch: env '{rust_target_sys}' != path '{target_triple}'"
+        )
 
 class RustHostCompileTest(OESDKTestCase):
     td_vars = ['MACHINE', 'SDK_SYS']