diff --git a/src/node_sea.cc b/src/node_sea.cc
index 1be41e6f14146e..b0382479b183d3 100644
--- a/src/node_sea.cc
+++ b/src/node_sea.cc
@@ -537,6 +537,14 @@ std::optional<SeaConfig> ParseSingleExecutableConfig(
     }
   }
 
+  if (!document.at_end()) {
+    FPrintF(stderr,
+            "Cannot parse JSON from %s: %s\n",
+            config_path,
+            simdjson::error_message(simdjson::TRAILING_CONTENT));
+    return std::nullopt;
+  }
+
   if (static_cast<bool>(result.flags & SeaFlags::kUseSnapshot) &&
       static_cast<bool>(result.flags & SeaFlags::kUseCodeCache)) {
     // TODO(joyeecheung): code cache in snapshot should be configured by
diff --git a/test/sea/test-single-executable-blob-config-errors.js b/test/sea/test-single-executable-blob-config-errors.js
index 322f430aad81d6..9562faad6b79d7 100644
--- a/test/sea/test-single-executable-blob-config-errors.js
+++ b/test/sea/test-single-executable-blob-config-errors.js
@@ -47,6 +47,24 @@ const { spawnSyncAndAssert } = require('../common/child_process');
     });
 }
 
+{
+  tmpdir.refresh();
+  const config = tmpdir.resolve('trailing-content.json');
+  writeFileSync(
+    config,
+    '{"main":"bundle.js","output":"sea.blob"}{}',
+    'utf8',
+  );
+  spawnSyncAndAssert(
+    process.execPath,
+    ['--experimental-sea-config', config], {
+      cwd: tmpdir.path,
+    }, {
+      status: 1,
+      stderr: /TRAILING_CONTENT/,
+    });
+}
+
 {
   tmpdir.refresh();
   const config = tmpdir.resolve('empty.json');